The efficient induction of human retinal ganglion-like cells provides a platform for studying optic neuropathies.

Retinal ganglion cells (RGCs) are essential for vision perception. In glaucoma and other optic neuropathies, RGCs and their optic axons undergo degenerative change and cell death; this can result in irreversible vision loss. Here we developed a rapid protocol for directly inducing RGC differentiation from human induced pluripotent stem cells (hiPSCs) by the overexpression of ATOH7, BRN3B, and SOX4. The hiPSC-derived RGC-like cells (iRGCs) show robust expression of various RGC-specific markers by whole transcriptome profiling. A functional assessment was also carried out and this demonstrated that these iRGCs display stimulus-induced neuronal activity, as well as spontaneous neuronal activity. Ethambutol (EMB), an effective first-line anti-tuberculosis agent, is known to cause serious visual impairment and irreversible vision loss due to the RGC degeneration in a significant number of treated patients. Using our iRGCs, EMB was found to induce significant dose-dependent and time-dependent increases in cell death and neurite degeneration. Western blot analysis revealed that the expression levels of p62 and LC3-II were upregulated, and further investigations revealed that EMB caused a blockade of lysosome-autophagosome fusion; this indicates that impairment of autophagic flux is one of the adverse effects of that EMB has on iRGCs. In addition, EMB was found to elevate intracellular reactive oxygen species (ROS) levels increasing apoptotic cell death. This could be partially rescued by the co-treatment with the ROS scavenger NAC. Taken together, our findings suggest that this iRGC model, which achieves both high yield and high purity, is suitable for investigating optic neuropathies, as well as being useful when searching for potential drugs for therapeutic treatment and/or disease prevention.

I-line photolithographic metalenses enabled by distributed optical proximity correction with a deep-learning model.

High pattern fidelity is paramount to the performance of metalenses and metasurfaces, but is difficult to achieve using economic photolithography technologies due to low resolutions and limited process windows of diverse subwavelength structures. These hurdles can be overcome by photomask sizing or reshaping, also known as optical proximity correction (OPC). However, the lithographic simulators critical to model-based OPC require precise calibration and have not yet been specifically developed for metasurface patterning. Here, we demonstrate an accurate lithographic model based on Hopkin's image formulation and fully convolutional networks (FCN) to control the critical dimension (CD) patterning of a near-infrared (NIR) metalens through a distributed OPC flow using i-line photolithography. The lithographic model achieves an average ΔCD/CD = 1.69% due to process variations. The model-based OPC successfully produces the 260 nm CD in a metalens layout, which corresponds to a lithographic constant k1 of 0.46 and is primarily limited by the resolution of the photoresist. Consequently, our fabricated NIR metalens with a diameter of 1.5 mm and numerical aperture (NA) of 0.45 achieves a measured focusing efficiency of 64%, which is close to the calculated value of 69% and among the highest reported values using i-line photolithography.

Lactoferrin Ameliorates Ovalbumin-Induced Asthma in Mice through Reducing Dendritic-Cell-Derived Th2 Cell Responses.

Asthma is a chronic respiratory disease with symptoms such as expiratory airflow narrowing and airway hyperresponsiveness (AHR). Millions of people suffer from asthma and are at risk of life-threatening conditions. Lactoferrin (LF) is a glycoprotein with multiple physiological functions, including antioxidant, anti-inflammatory, antimicrobial, and antitumoral activities. LF has been shown to function in immunoregulatory activities in ovalbumin (OVA)-induced delayed type hypersensitivity (DTH) in mice. Hence, the purpose of this study was to investigate the roles of LF in AHR and the functions of dendritic cells (DCs) and Th2-related responses in asthma. Twenty 8-week-old male BALB/c mice were divided into normal control (NC), ovalbumin (OVA)-sensitized, and OVA-sensitized with low dose of LF (100 mg/kg) or high dose of LF (300 mg/kg) treatment groups. The mice were challenged by intranasal instillation with 5% OVA on the 21st to 27th day after the start of the sensitization period. The AHR, cytokines in bronchoalveolar lavage fluid, and pulmonary histology of each mouse were measured. Serum OVA-specific IgE and IgG1 and OVA-specific splenocyte responses were further detected. The results showed that LF exhibited protective effects in ameliorating AHR, as well as lung inflammation and damage, in reducing the expression of Th2 cytokines and the secretion of allergen-specific antibodies, in influencing the functions of DCs, and in decreasing the level of Th2 immune responses in a BALB/c mouse model of OVA-induced allergic asthma. Importantly, we demonstrated that LF has practical application in reducing DC-induced Th2 cell responses in asthma. In conclusion, LF exhibits anti-inflammation and immunoregulation activities in OVA-induced allergic asthma. These results suggest that LF may act as a supplement to prevent asthma-induced lung injury and provide an additional agent for reducing asthma severity.

General single-index survival regression models for incident and prevalent covariate data and prevalent data without follow-up.

This article mainly focuses on analyzing covariate data from incident and prevalent cohort studies and a prevalent sample with only baseline covariates of interest and truncation times. Our major task in both research streams is to identify the effects of covariates on a failure time through very general single-index survival regression models without observing survival outcomes. With a strict increase of the survival function in the linear predictor, the ratio of incident and prevalent covariate densities is shown to be a non-degenerate and monotonic function of the linear predictor under covariate-independent truncation. Without such a structural assumption, the conditional density of a truncation time in a prevalent cohort is ensured to be a non-degenerate function of the linear predictor. In light of these features, some innovative approaches, which are based on the maximum rank correlation estimation or the pseudo least integrated squares estimation, are developed to estimate the coefficients of covariates up to a scale factor. Existing theoretical results are further used to establish the n -consistency and asymptotic normality of the proposed estimators. Moreover, extensive simulations are conducted to assess and compare the finite-sample performance of various estimators. To illustrate the methodological ideas, we also analyze data from the Worcester Heart Attack Study and the National Comorbidity Survey Replication.

High CEA levels in a case of resected colorectal cancer: delayed diagnosis of metachronous medullary thyroid cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers, and its value in the surveillance of post-operative colorectal cancer is well established. Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been clinically used in colorectal cancer imaging including preoperative staging, evaluation of therapeutic response, detection of disease recurrence, and investigation of unexplained rising tumor markers. CASE PRESENTATION: We report a case of resected colorectal cancer presented with rising CEA levels in 5 years, and FDG-PET revealed no definitive evidence of recurrence except abnormal focal FDG uptake in the right thyroid lobe. However, fine needle aspiration cytology (FNAC) of the thyroid nodule showed negative for malignancy. Progressively rising CEA levels were noted over the following 5 years, but serial follow-up examinations did not find evidence of recurrence. Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) was performed subsequently and again showed focal FDG uptake in the right thyroid lobe. This time, FNAC revealed positive for malignancy, in favor of medullary thyroid carcinoma (MTC). The patient underwent total thyroidectomy and modified radical neck dissection, and MTC with cervical nodal metastasis (pT3N1) was diagnosed. He had cervical lymph nodes recurrence 2 years later, which was resected. CONCLUSIONS: This case reminded us that FDG-PET/CT may detect occult tumors resulting in CEA elevation other than colorectal cancer. Moreover, FNA has a higher false negative rate in detecting MTC than other forms of thyroid cancer. Repeat FNAC for the initial negative cytology result and measure of serum calcitonin for the early MTC detection could be more helpful to avoid the delay in MTC diagnosis.

Dynamic expression of epidermal caspase 8 simulates a wound healing response.

Tissue homeostasis and regeneration are regulated by an intricate balance of seemingly competing processes-proliferation versus differentiation, and cell death versus survival. Here we demonstrate that the loss of epidermal caspase 8, an important mediator of apoptosis, recapitulates several phases of a wound healing response in the mouse. The epidermal hyperplasia in the caspase 8 null skin is the culmination of signals exchanged between epidermal keratinocytes, dermal fibroblasts and leukocytic cells. This reciprocal interaction is initiated by the paracrine signalling of interleukin 1alpha (IL1alpha), which activates both skin stem cell proliferation and cutaneous inflammation. The non-canonical secretion of IL1alpha is induced by a p38-MAPK-mediated upregulation of NALP3 (also known as NLRP3), leading to inflammasome assembly and caspase 1 activation. Notably, the increased proliferation of basal keratinocytes is counterbalanced by the growth arrest of suprabasal keratinocytes in the stratified epidermis by IL1alpha-dependent NFkappaB signalling. Altogether, our findings illustrate how the loss of caspase 8 can affect more than programmed cell death to alter the local microenvironment and elicit processes common to wound repair and many neoplastic skin disorders.

Development of atopic dermatitis-like skin disease from the chronic loss of epidermal caspase-8.

Atopic dermatitis is an inflammatory skin disease that affects approximately 20% of children worldwide. Left untreated, the barrier function of the skin is compromised, increasing susceptibility to dehydration and infection. Despite its prevalence, its multifactorial nature has complicated the unraveling of its etiology. We found that chronic loss of epidermal caspase-8 recapitulates many aspects of atopic dermatitis, including a spongiotic phenotype whereby intercellular adhesion between epidermal keratinocytes is disrupted, adversely affecting tissue architecture and function. Although spongiosis is generally thought to be secondary to edema, we found that suppression of matrix metalloproteinase-2 activity is sufficient to abrogate this defect. p38 MAPK induces matrix metalloproteinase-2 expression to cleave E-cadherin, which mediates keratinocyte cohesion in the epidermis. Thus, the conditional loss of caspase-8, which we previously found to mimic a wound response, can be used to gain insights into how these same wound-healing processes are commandeered in inflammatory skin diseases.

Directed Differentiation of Human iPSCs into Microglia-Like Cells Using Defined Transcription Factors.

The generation of a homogeneous population of microglia from human induced pluripotent stem cells (hiPSCs) is crucial to modeling neurological disorders, as well as the carrying out of drug screening and toxicity testing. Here, we provide a stepwise protocol for the simple, robust, and efficient differentiation of hiPSCs into microglia-like cells (iMGs) by overexpression of SPI1 and CEBPA. This protocol details hiPSC culture, lentivirus production, lentivirus delivery, and, finally, the differentiation and validation of the iMG cells.

Glycans on influenza hemagglutinin affect receptor binding and immune response.

Recent cases of avian influenza H5N1 and the swine-origin 2009 H1N1 have caused a great concern that a global disaster like the 1918 influenza pandemic may occur again. Viral transmission begins with a critical interaction between hemagglutinin (HA) glycoprotein, which is on the viral coat of influenza, and sialic acid (SA) containing glycans, which are on the host cell surface. To elucidate the role of HA glycosylation in this important interaction, various defined HA glycoforms were prepared, and their binding affinity and specificity were studied by using a synthetic SA microarray. Truncation of the N-glycan structures on HA increased SA binding affinities while decreasing specificity toward disparate SA ligands. The contribution of each monosaccharide and sulfate group within SA ligand structures to HA binding energy was quantitatively dissected. It was found that the sulfate group adds nearly 100-fold (2.04 kcal/mol) in binding energy to fully glycosylated HA, and so does the biantennary glycan to the monoglycosylated HA glycoform. Antibodies raised against HA protein bearing only a single N-linked GlcNAc at each glycosylation site showed better binding affinity and neutralization activity against influenza subtypes than the fully glycosylated HAs elicited. Thus, removal of structurally nonessential glycans on viral surface glycoproteins may be a very effective and general approach for vaccine design against influenza and other human viruses.

Analysis of building envelope insulation performance utilizing integrated temperature and humidity sensors.

A major cause of high energy consumption for air conditioning in indoor spaces is the thermal storage characteristics of a building's envelope concrete material; therefore, the physiological signals (temperature and humidity) within concrete structures are an important reference for building energy management. The current approach to measuring temperature and humidity within concrete structures (i.e., thermocouples and fiber optics) is limited by problems of wiring requirements, discontinuous monitoring, and high costs. This study uses radio frequency integrated circuits (RFIC) combined with temperature and humidity sensors (T/H sensors) for the design of a smart temperature and humidity information material (STHIM) that automatically, regularly, and continuously converts temperature and humidity signals within concrete and transmits them by radio frequency (RF) to the Building Physiology Information System (BPIS). This provides a new approach to measurement that incorporates direct measurement, wireless communication, and real-time continuous monitoring to assist building designers and users in making energy management decisions and judgments.

Exposure to Air Pollutants Increases the Risk of Chronic Rhinosinusitis in Taiwan Residents.

Air pollution triggers a tissue-specific inflammatory response. However, studies on the association between exposure to air pollutants and chronic rhinosinusitis (CRS) risk remain limited. Thus, we conducted this nationwide study to define the association between air pollution and CRS. We used the Longitudinal Health Insurance Database (LHID) and Taiwan Air Quality-Monitoring Database (TAQMD) to conduct a population-based cohort study. Study participants were recruited from the LHID, a data subset of the National Health Insurance Research Database that randomly sampled one million individuals. TAQMD has been an air pollutant database since 1998. In univariate and multivariate Cox proportional hazards regression models, adjusted hazard ratios (aHRs) and 95% CIs of CRS in five air pollutants were accounted. We adjusted for age, sex, urbanization level, insurance fee, comorbidities, and pollutant levels in the multivariate model. The total number of participants enrolled in this study was 160,504. The average age was 40.46 ± 14.62 years; males constituted 43.8% of the total participants. The percentages of alcoholism, tobacco dependence, and COPD were 1.5%, 2.8%, and 28.3%, respectively. After adjustment for age, sex, urbanization level, insurance fee, and comorbidities, the highest levels of air pollutants, including PM2.5 (aHR = 1.14, 95% CI = 1.06-1.22), NO2 (aHR = 1.07, 95% CI = 1.00-1.15), and PM10 (aHR = 1.13, 95% CI = 1.05-1.21) had a significantly greater CRS risk; we selected the lower concentration as the reference but did not correlate with CO. We found a significantly increased risk of CRS in residents with air pollutant exposure.

Synthesis of BiFeO3/ZnO core-shell hetero-structures using ZnO nanorod positive templates.

We report the synthesis, morphology, and magnetization characteristics of BiFeO(3) (BFO)-covered ZnO nanorod arrays (ZNAs). High quality and well-aligned ZNAs were grown by a hydrothermal method. BFO shells were deposited by sputtering at ambient temperature and then annealing in an oxygen atmosphere. The BFO shells crystallized to form a perovskite structure at 450 °C. Scanning electron microscopy and high resolution transmission electron microscopy demonstrated that the BFO shell was polycrystalline and randomly oriented, covering the ZnO nanorods well. The magnetization-magnetic field loops measured at 5 and 300 K indicate that the BFO/ZNA hetero-structure exhibits ferromagnetic order. The BFO/ZNA displays enhanced coercivity and saturated magnetization as compared with BFO thin films.

Effect of mitochondrial dysfunction and oxidative stress on endogenous levels of coenzyme Q(10) in human cells.

Little is known about the regulation of endogenous CoQ(10) levels in response to mitochondrial dysfunction or oxidative stress although exogenous CoQ(10) has been extensively used in humans. In this study, we first demonstrated that acute treatment of antimycin A, an inhibitor of mitochondrial complex III, and the absence of mitochondrial DNA suppressed CoQ(10) levels in human 143B cells. Because these two conditions also enhanced formation of reactive oxygen species (ROS), we further investigated whether oxidative stress or mitochondrial dysfunction primarily contributed to the decrease of CoQ(10) levels. Results showed that H(2)O(2) augmented CoQ(10) levels, but carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), a chemical uncoupler, decreased CoQ(10) levels in 143B cells. However, H(2)O(2) and FCCP both increased mRNA levels of multiple COQ genes for biosynthesis of CoQ(10) . Our findings suggest that ROS induced CoQ(10) biosynthesis, whereas mitochondrial energy deficiency caused secondary suppression of CoQ(10) levels possibly due to impaired import of COQ proteins into mitochondria.

Quantification and recognition of parkinsonian gait from monocular video imaging using kernel-based principal component analysis.

BACKGROUND: The computer-aided identification of specific gait patterns is an important issue in the assessment of Parkinson's disease (PD). In this study, a computer vision-based gait analysis approach is developed to assist the clinical assessments of PD with kernel-based principal component analysis (KPCA). METHOD: Twelve PD patients and twelve healthy adults with no neurological history or motor disorders within the past six months were recruited and separated according to their "Non-PD", "Drug-On", and "Drug-Off" states. The participants were asked to wear light-colored clothing and perform three walking trials through a corridor decorated with a navy curtain at their natural pace. The participants' gait performance during the steady-state walking period was captured by a digital camera for gait analysis. The collected walking image frames were then transformed into binary silhouettes for noise reduction and compression. Using the developed KPCA-based method, the features within the binary silhouettes can be extracted to quantitatively determine the gait cycle time, stride length, walking velocity, and cadence. RESULTS AND DISCUSSION: The KPCA-based method uses a feature-extraction approach, which was verified to be more effective than traditional image area and principal component analysis (PCA) approaches in classifying "Non-PD" controls and "Drug-Off/On" PD patients. Encouragingly, this method has a high accuracy rate, 80.51%, for recognizing different gaits. Quantitative gait parameters are obtained, and the power spectrums of the patients' gaits are analyzed. We show that that the slow and irregular actions of PD patients during walking tend to transfer some of the power from the main lobe frequency to a lower frequency band. Our results indicate the feasibility of using gait performance to evaluate the motor function of patients with PD. CONCLUSION: This KPCA-based method requires only a digital camera and a decorated corridor setup. The ease of use and installation of the current method provides clinicians and researchers a low cost solution to monitor the progression of and the treatment to PD. In summary, the proposed method provides an alternative to perform gait analysis for patients with PD.

Determinants of Consumers' Trust in Biotech Brands and Purchase Intentions towards the Cord Blood Products.

The development of the biotech industry is in full swing, and consumers have begun to value biotech brands. Since biotech products often focus on the future or special benefits, consumers inevitably bear certain risks when purchasing biotech products, and their trust in the biotech brand will have an important impact on their purchase intention. Previous studies have lacked a targeted understanding of consumer trust in biotech brands and a discussion of cultural viewpoints. This study introduced the concept of personal connections in Chinese relationalism and trust strategies in Chinese society to address this gap. In-depth interviews and focus group discussions were conducted in collaboration with Company X, a listed Taiwanese cord blood company, to extract the key factors influencing consumer trust and purchase intention of biotech brands. After constructing the structure model, the study was validated using a structural equation model through investigation and survey. The findings indicated that consumer trust in biotech brands was constructed by a combination of kinship trust transfer and emergent trust transfer within the consumer relationship network, as well as institutional trust and professional trust outside the relationship network and that a significant positive correlation existed between consumer trust in biotech brands and purchase intention. The acquaintances within the consumer relationship network include not only relatives and friends but also health care workers and netizens that consumers come into contact with. In addition, kinship trust transfer and emergent trust transfer within the consumer relationship network have a greater impact on trust in biotech brands than the institutional trust and professional trust outside the relationship network. The findings of this study deepen the understanding of consumer trust in biotech brands across cultures, and suggest that future marketing communication should be expanded to include key players within the consumer relationship network.

Efficient conversion of human induced pluripotent stem cells into microglia by defined transcription factors.

Microglia, the immune cells of the central nervous system, play critical roles in brain physiology and pathology. We report a novel approach that produces, within 10 days, the differentiation of human induced pluripotent stem cells (hiPSCs) into microglia (iMG) by forced expression of both SPI1 and CEBPA. High-level expression of the main microglial markers and the purity of the iMG cells were confirmed by RT-qPCR, immunostaining, and flow cytometry analyses. Whole-transcriptome analysis demonstrated that these iMGs resemble human fetal/adult microglia but not human monocytes. Moreover, these iMGs exhibited appropriate physiological functions, including various inflammatory responses, ADP/ATP-evoked migration, and phagocytic ability. When co-cultured with hiPSC-derived neurons, the iMGs respond and migrate toward injured neurons. This study has established a protocol for the rapid conversion of hiPSCs into functional iMGs, which should facilitate functional studies of human microglia using different disease models and also help with drug discovery.

The preparation of silver nanoparticle decorated silica nanowires on fused quartz as reusable versatile nanostructured surface-enhanced Raman scattering substrates.

We introduce a platform, comprised of silver nanoparticle decorated silica nanowires (SiONWs) dispersed on fused quartz substrates, for high sensitivity surface-enhanced Raman scattering (SERS) measurements using both frontal (through the analytes) and back-face (through the transparent substrate) excitation. Quasi-quantitative SERS performances on the specialized substrate, vis-à-vis a silver deposited bare fused quartz plate, showed: (i) the suitability of the Ag modified SiONW substrate for frontal as well as back-face excitation; (ii) a wider detection range with high sensitivity to Rhodamine 6G; and (iii) good underwater metal-oxide adhesion of the specialized substrates. Capable of surviving ultrasonic cleaning, the substrate introduced is one of the few reusable low-cost Ag-based nanostructured SERS substrates, requiring only a simple silver reload process (the silver mirror reaction).

Novel electrochemical synthesis of cellulose microfiber entrapped reduced graphene oxide: A sensitive electrochemical assay for detection of fenitrothion organophosphorus pesticide.

Over the past decades, the synthesis of carbohydrate polymers incorporated graphene or reduced graphene oxide has received greater attention in different disciplines owing to their unique physicochemical properties. In this context, we report a facile electrochemical synthesis of cellulose microfibers supported reduced graphene oxide and its application towards enhanced and lower potential electrochemical detection of fenitrothion. The synthesized cellulose microfibers supported reduced graphene oxide composite was further characterized using Fourier-transform infrared spectroscopy, Raman spectroscopy and high resolution scanning electron microscopy. Cyclic voltammetry studies reveal that cellulose microfibers supported reduced graphene oxide composite modified screen-printed carbon electrode exhibits a superior electro-reduction ability and lower reduction potential towards fenitrothion compared to screen-printed carbon electrodes modified with graphene oxide, graphene oxide-cellulose microfibers, and reduced graphene oxide. Furthermore, cellulose microfibers supported reduced graphene oxide composite modified electrode showed 141 mV lower reduction potential towards fenitrothion than the chemically reduced graphene oxide- cellulose microfibers composite modified screen-printed carbon electrode. The effect of accumulation time, catalyst loading, scan rate and pH for the detection of fenitrothion has been studied and discussed. Differential pulse voltammetric studies show that the fabricated composite electrode can detect the fenitrothion in a wider linear response range up to 1.134 mM with a detection limit of 8 nM. To validate the proof of concept, the fabricated sensor was successfully applied for the detection of fenitrothion in different water samples.

Establishing the waist as the better location for attaching a single accelerometer to estimate center of pressure trajectories.

BACKGROUND: In this study, we seek to replace conventional force platforms with a single accelerometer for measuring Center of Pressure trajectories, in order to achieve portability and convenience without sacrificing accuracy. METHODS: We measure the actual Anterior/Posterior and Medial/Lateral Center of Pressure trajectories of ten healthy young subjects using a force platform, and compare them with estimated measurements derived from accelerometer signals collected from three body locations (upper trunk, waist, and lower thigh) using three machine learning algorithms (Neural Network, Genetic Algorithm, and Adaptive Network-based Fuzzy Inference System). Error ratios and correlation coefficients corresponding to body locations were compared via one-way repeated-measures ANOVA. The ratios and coefficients corresponding to the three algorithms were also compared using the same approach. FINDINGS: Estimated Anterior/Posterior trajectories indicated that measurements collected from the waist provided the lowest margins of error (8.1-8.4% v. 12.1-13.4%, P ≤ .001) and the highest correlation (.95 v. .82-.86, P ≤ .032). Estimated Medial/Lateral trajectories indicated that measurements collected from both the waist and thigh, as compared to the upper trunk, provided lower margins of error (7.0-7.3% v. 8.5-10.8%). In general, the waist is the better accelerometer attachment location. INTERPRETATION: The results of our study corroborate our deduction that the high correlation between Center of Pressure and body's Center of Mass provides the rationale to place the single accelerometer close to the waist for Center of Pressure estimations. This study also supports the feasibility of using one single accelerometer programmed with algorithms for similar clinical applications.

Rothia dentocariosa bacteremia in children: report of two cases and review of the literature.

Rothia dentocariosa, a pleomorphic, fastidious, Gram-positive rod, is a normal inhabitant of the oropharynx. It is a well-known causative agent of dental plaques and periodontal disease. Generally regarded as of low virulence to humans, R. dentocariosa has been increasingly recognized as a pathogen in adults and often associated with infective endocarditis. It should not necessarily be regarded as a contaminant when the isolate comes from areas other than the oropharynx, especially from the blood. We report two cases of R. dentocariosa bacteremia, including an 8-month-old boy with repaired transposition of the great arteries, and a healthy 20-month-old girl with herpangina.