Contrast-Enhanced Ultrasound of the Chest in Children and Adolescents: A Pilot Study for Assessment of Added Diagnostic Value.

OBJECTIVES: To determine the added diagnostic value of contrast-enhanced ultrasound (CEUS) in pediatric chest abnormalities by comparing interpretation of CEUS studies and confidence level to conventional US studies. METHODS: CEUS studies in patients with a variety of clinically suspected chest abnormalities performed between 2016 and 2020 were reviewed and compared to same-day conventional US studies. Examinations were independently interpreted by 4 radiologists blinded to clinical and other imaging data. Rater confidence was classified as low, moderate, or high. Diagnostic accuracy was determined by comparing image interpretation to patient outcome as the ground truth. Interobserver agreement was also assessed. RESULTS: Sixteen patients (10 male) with 18 CEUS studies were included. Median rater agreement with ground truth was significantly higher for CEUS (100%) than conventional US (50%; P = .004). Median rater confidence was high (3.0) for CEUS, and low-moderate (1.5) for conventional US (P < .001). CEUS sensitivity (54.6-81.8%) and specificity (63.4-100.0%) were greater than conventional US (45.5-72.7% and 12.5-63.5%, respectively). CEUS false positives (0-4) and false negatives (2-5) were fewer than conventional US (4-7 and 3-6, respectively). Except for one rater pair where agreement was substantial (κ = .78, P < .01), inter-rater agreement for CEUS for all other rater pairs was nonsignificant (κ = .25-0.51, P ≥ .07). Agreement for conventional US was moderate and statistically significant for 3 rater pairs (κ = .55-0.78) and nonsignificant for the remaining 3 rater pairs (P ≥ .06). CONCLUSIONS: CEUS adds diagnostic value to the assessment of a variety of chest abnormalities. The data support further evaluation of the role of CEUS as a non-invasive, problem-solving technique in children.

Bacterial osteomyelitis in pediatric patients: a comprehensive review.

Bacterial osteomyelitis, an inflammatory response in the bone caused by microorganisms, typically affects the metaphysis in the skeletally immature. Bacterial osteomyelitis possesses a significant diagnostic challenge in pediatric patients due to its nonspecific clinical presentation. Because the metaphysis is the primary focus of infection in skeletally immature patients, understanding the normal physiologic, maturation process of bones throughout childhood allows to understand the pathophysiology of osteomyelitis. Timely and accurate diagnosis is crucial to initiate appropriate treatment, and prevent long-term sequelae and efforts must be made to isolate the causative organism. The potential causative organism changes according to the age of the patient and underlying medical conditions. Staphylococcus Aureus is the most common isolated bacteria in pediatric pyogenic osteomyelitis whereas Kingella Kingae is the most common causative agent in children aged 6 months to 4 years. Imaging plays a pivotal role in the diagnosis, characterization, evaluation of complications, and follow up of bacterial osteomyelitis. Imaging also plays a pivotal role in the evaluation of potential neoplastic and non-neoplastic mimickers of osteomyelitis. In children, MRI is currently the gold standard imaging modality when suspecting bacterial osteomyelitis, whereas surgical intervention may be required in order to isolate the microorganism, treat complications, and exclude mimickers.

The association of therapist empathy and synchrony in vocally encoded arousal.

Empathy is a critical ingredient in motivational interviewing (MI) and in psychotherapy generally. It is typically defined as the ability to experience and understand the feelings of another. Basic science indicates that empathy is related to the development of synchrony in dyads. However, in clinical research, empathy has proved difficult to operationalize and measure, and has mostly relied on the felt sense of observers, clients, or therapists. We extracted estimates of therapist and standardized patient (SP) vocally encoded arousal (mean fundamental frequency; mean f0) in 89 MI sessions with high and low empathy ratings from independent observers. We hypothesized (a) therapist and SP mean f0 would be correlated and (b) the correlation of therapist and SP mean f0 would be greater in sessions with high empathy as compared with low. On the basis of a multivariate mixed model, the correlation between therapist and SP mean f0 was large (r = .71) and close to 0 in randomly assigned therapist-SP dyads (r = -.08). The association was higher in sessions with high empathy ratings (r = .80) than in sessions with low ratings (r = .36). There was strong evidence for vocal synchrony in clinical dyads as well as for the association of synchrony with empathy ratings, illustrating the relevance of basic psychological processes to clinical interactions. These findings provide initial evidence for an objective and nonobtrusive method for assessing therapist performance. Novel indicators of therapist empathy may have implications for the study of MI process as well as the training of therapists generally. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Effects of Activation Barriers on Quenching to Stabilize Prebiotic Chemical Systems.

We have previously shown in model studies that rapid quenches of systems of monomers interacting to form polymer chains can fix nonequilibrium chemistries with some lifelike properties. We suggested that such quenching processes might have occurred at very high rates on early Earth, giving an efficient mechanism for natural sorting through enormous numbers of nonequilibrium chemistries from which the most lifelike ones could be naturally selected. However, the model used for these studies did not take account of activation barriers to polymer scission (peptide bond hydrolysis in the case of proteins). Such barriers are known to exist and are expected to enhance the quenching effect. Here, we introduce a modified model which takes activation barriers into account and we compare the results to data from experiments on quenched systems of amino acids. We find that the model results turn out to be sensitive to the width of the distribution of barrier heights but quite insensitive to its average value. The results of the new model are in significantly better agreement with the experiments than those found using our previous model. The new parametrization of the model only requires one new parameter and the parametrization is more physical than the previous one, providing a chemical interpretation of the parameter p in our previous models. Within the model, a characteristic temperature Tc emerges such that if the temperature of the hot stage is above Tc and the temperature of the cold stage is below it, then the 'freezing out', in a quench, of a disequilibrium ensemble of long polymers is expected. We discuss the possible relevance of this to models of the origin of life in emissions from deep ocean rifts.

Long-term and baseline recreational physical activity and risk of endometrial cancer: the California Teachers Study.

BACKGROUND: Physical activity may be associated with decreasing endometrial cancer risk; it remains unclear whether the association is modified by body size. METHODS: Among 93 888 eligible California Teachers Study participants, 976 were diagnosed with incident endometrial cancer between 1995-1996 and 2007. Cox proportional hazards regression methods were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with long-term (high school through age 54 years) and baseline (3 years prior to joining the cohort) strenuous and moderate recreational physical activity, overall and by body size. RESULTS: Increased baseline strenuous recreational physical activity was associated with decreased endometrial cancer risk (Ptrend=0.006) with approximately 25% lower risk among women exercising >3 h per week per year than among those exercising <1/2 h per week per year (RR, 0.76; 95% CI, 0.63-0.92). This inverse association was observed among overweight/obese women (body mass index ≥25 kg m(-2); Ptrend=0.006), but not among thinner women (Ptrend=0.12). Baseline moderate activity was associated with lower risk among overweight/obese women. CONCLUSION: Increasing physical activity, particularly strenuous activity, may be a lifestyle change that overweight and obese women can implement to reduce their endometrial cancer risk.

Validation of Rosner-Colditz breast cancer incidence model using an independent data set, the California Teachers Study.

To validate an established breast cancer incidence model in an independent prospective data set. After aligning time periods for follow-up, we restricted populations to comparable age ranges (47-74 years), and followed them for incident invasive breast cancer (follow-up 1994-2008, Nurses' Health Study [NHS]; and 1995-2009, California Teachers Study [CTS]). We identified 2026 cases during 540,617 person years of follow-up in NHS, and 1,400 cases during 288,111 person years in CTS. We fit the Rosner-Colditz log-incidence model and the Gail model using baseline data. We imputed future use of hormones based on type and prior duration of use and other covariates. We assessed performance using area under the curve (AUC) and calibration methods. Participants in the CTS had fewer children, were leaner, consumed more alcohol, and were more frequent users of postmenopausal hormones. Incidence rate ratios for breast cancer showed significantly higher breast cancer in the CTS (IRR = 1.32, 95 % CI 1.24-1.42). Parameters for the log-incidence model were comparable across the two cohorts. Overall, the NHS model performed equally well when applied in the CTS. In the NHS the AUC was 0.60 (s.e. 0.006) and applying the NHS betas to the CTS the performance in the independent data set (validation) was 0.586 (s.e. 0.009). The Gail model gave values of 0.547 (s.e. 0.008), a significant 4 % lower, p < 0.0001. For women 47-69 the AUC values for the log-incidence model are 0.608 in NHS and 0.609 in CTS; and for Gail are 0.569 and 0.572. In both cohorts, performance of both models dropped off in older women 70-87, and later in follow-up (6-12 years). Calibration showed good estimation against SEER with a non-significant 4 % underestimate of overall breast cancer incidence when applying the model in the CTS population (p = 0.098). The Rosner-Colditz model performs consistently well when applied in an independent data set. Performance is stronger predicting incidence among women 47-69 and over a 5-year time interval. AUC values exceed those for Gail by 3-5 % based on AUC when both are applied to the independent validation data set. Models may be further improved with addition of breast density or other markers of risk beyond the current model.

CO2 capture properties of lithium silicates with different ratios of Li2O/SiO2: an ab initio thermodynamic and experimental approach.

The lithium silicates have attracted scientific interest due to their potential use as high-temperature sorbents for CO2 capture. The electronic properties and thermodynamic stabilities of lithium silicates with different Li2O/SiO2 ratios (Li2O, Li8SiO6, Li4SiO4, Li6Si2O7, Li2SiO3, Li2Si2O5, Li2Si3O7, and α-SiO2) have been investigated by combining first-principles density functional theory with lattice phonon dynamics. All these lithium silicates examined are insulators with band-gaps larger than 4.5 eV. By decreasing the Li2O/SiO2 ratio, the first valence bandwidth of the corresponding lithium silicate increases. Additionally, by decreasing the Li2O/SiO2 ratio, the vibrational frequencies of the corresponding lithium silicates shift to higher frequencies. Based on the calculated energetic information, their CO2 absorption capabilities were extensively analyzed through thermodynamic investigations on these absorption reactions. We found that by increasing the Li2O/SiO2 ratio when going from Li2Si3O7 to Li8SiO6, the corresponding lithium silicates have higher CO2 capture capacity, higher turnover temperatures and heats of reaction, and require higher energy inputs for regeneration. Based on our experimentally measured isotherms of the CO2 chemisorption by lithium silicates, we found that the CO2 capture reactions are two-stage processes: (1) a superficial reaction to form the external shell composed of Li2CO3 and a metal oxide or lithium silicate secondary phase and (2) lithium diffusion from bulk to the surface with a simultaneous diffusion of CO2 into the shell to continue the CO2 chemisorption process. The second stage is the rate determining step for the capture process. By changing the mixing ratio of Li2O and SiO2, we can obtain different lithium silicate solids which exhibit different thermodynamic behaviors. Based on our results, three mixing scenarios are discussed to provide general guidelines for designing new CO2 sorbents to fit practical needs.

Applying complex models to poultry production in the future--economics and biology.

The ability to determine the optimal broiler feed nutrient density that maximizes margin over feeding cost (MOFC) has obvious economic value. To determine optimal feed nutrient density, one must consider ingredient prices, meat values, the product mix being marketed, and the projected biological performance. A series of 8 feeding trials was conducted to estimate biological responses to changes in ME and amino acid (AA) density. Eight different genotypes of sex-separate reared broilers were fed diets varying in ME (2,723-3,386 kcal of ME/kg) and AA (0.89-1.65% digestible lysine with all essential AA acids being indexed to lysine) levels. Broilers were processed to determine carcass component yield at many different BW (1.09-4.70 kg). Trial data generated were used in model constructed to discover the dietary levels of ME and AA that maximize MOFC on a per broiler or per broiler annualized basis (bird × number of cycles/year). The model was designed to estimate the effects of dietary nutrient concentration on broiler live weight, feed conversion, mortality, and carcass component yield. Estimated coefficients from the step-wise regression process are subsequently used to predict the optimal ME and AA concentrations that maximize MOFC. The effects of changing feed or meat prices across a wide spectrum on optimal ME and AA levels can be evaluated via parametric analysis. The model can rapidly compare both biological and economic implications of changing from current practice to the simulated optimal solution. The model can be exploited to enhance decision making under volatile market conditions.

Decreased serotonin transporter activity in the mitral valve contributes to progression of degenerative mitral regurgitation.

Degenerative mitral valve (MV) regurgitation (MR) is a highly prevalent heart disease that requires surgery in severe cases. Here, we show that a decrease in the activity of the serotonin transporter (SERT) accelerates MV remodeling and progression to MR. Through studies of a population of patients with MR, we show that selective serotonin reuptake inhibitor (SSRI) use and SERT promoter polymorphism 5-HTTLPR LL genotype were associated with MV surgery at younger age. Functional characterization of 122 human MV samples, in conjunction with in vivo studies in SERT-/- mice and wild-type mice treated with the SSRI fluoxetine, showed that diminished SERT activity in MV interstitial cells (MVICs) contributed to the pathophysiology of MR through enhanced serotonin receptor (HTR) signaling. SERT activity was decreased in LL MVICs partially because of diminished membrane localization of SERT. In mice, fluoxetine treatment or SERT knockdown resulted in thickened MV leaflets. Similarly, silencing of SERT in normal human MVICs led to up-regulation of transforming growth factor ß1 (TGFß1) and collagen (COL1A1) in the presence of serotonin. In addition, treatment of MVICs with fluoxetine not only directly inhibited SERT activity but also decreased SERT expression and increased HTR2B expression. Fluoxetine treatment and LL genotype were also associated with increased COL1A1 expression in the presence of serotonin in MVICs, and these effects were attenuated by HTR2B inhibition. These results suggest that assessment of both 5-HTTLPR genotype and SERT-inhibiting treatments may be useful tools to risk-stratify patients with MV disease to estimate the likelihood of rapid disease progression.

Self consistent tight binding model for dissociable water.

We report results of development of a self consistent tight binding model for water. The model explicitly describes the electrons of the liquid self consistently, allows dissociation of the water and permits fast direct dynamics molecular dynamics calculations of the fluid properties. It is parameterized by fitting to first principles calculations on water monomers, dimers, and trimers. We report calculated radial distribution functions of the bulk liquid, a phase diagram and structure of solvated protons within the model as well as ac conductivity of a system of 96 water molecules of which one is dissociated. Structural properties and the phase diagram are in good agreement with experiment and first principles calculations. The estimated DC conductivity of a computational sample containing a dissociated water molecule was an order of magnitude larger than that reported from experiment though the calculated ratio of proton to hydroxyl contributions to the conductivity is very close to the experimental value. The conductivity results suggest a Grotthuss-like mechanism for the proton component of the conductivity.

Some Factors from Theory, Simulation, Experiment and Proteomes in the Current Biosphere Supporting Deep Oceans as the Location of the Origin of Terrestrial Life.

Some standard arguments are reviewed supporting deep ocean trenches as a likely location for the origin of terrestrial life. An analysis of proteomes of contemporary prokaryotes carried out by this group is cited as supporting evidence, indicating that the original proteins were formed by quenching from temperatures close to the boiling point of water. Coarse-grained simulations of the network formation process which agree quite well with experiments of such quenches both in drying and rapid fluid emission from a hot to a cold fluid are also described and cited as support for such a scenario. We suggest further experiments, observations and theoretical and simulation work to explore this hypothesis.

Thoracic MDCT findings of a combined congenital lung lesion: Bronchial atresia associated with congenital pulmonary airway malformation.

PURPOSE: To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven combined congenital lung lesion consisting of bronchial atresia (BA) and congenital pulmonary airway malformation (CPAM) in children. MATERIALS AND METHODS: All pediatric patients (age ≤ 18 years) with a known pathological diagnosis of a combined BA-CPAM congenital lung lesion, who underwent thoracic MDCT studies from January 2011 to January 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung, including nodule, mass, cyst, ground-glass opacity, and consolidation. When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), borders (well-circumscribed vs. ill-defined), contrast enhancement pattern (nonenhancement vs. enhancement), and location (laterality, and lobar distribution) were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics. RESULTS: Eighteen contrast-enhanced thoracic MDCT studies from 18 individual pediatric patients (8 males (44%) and 10 females (56%); mean age: 4.9 months; SD: 2.6; range: 1-10 months) with a pathological diagnosis of combined BA-CPAM congenital lung lesion comprised the final study population. The most frequent MDCT finding of combined BA-CPAM congenital lung lesion in children was a solitary (18/18; 100%), well-circumscribed (18/18; 100%), both solid and cystic (17/18; 94%) lesion with nonenhancing (17/17; 100%) nodule, reflecting the underlying BA component, adjacent to a well-circumscribed multicystic mass (18/18; 100%), representing the underlying CPAM component. This combined congenital lung lesion occurred in all lobes with similar frequency. There was almost perfect interobserver κ agreement between the two independent reviewers for detecting abnormalities on thoracic MDCT studies (k = 0.98). CONCLUSION: The characteristic thoracic MDCT findings of a combined BA-CPAM congenital lung lesion are a solitary, well-circumscribed solid and multicystic mass, with a nonenhancing nodule, reflecting the BA component, adjacent to a cystic mass, representing the CPAM component. Accurate recognition of these characteristic MDCT findings of combined BA-CPAM congenital lung lesion has great potential to help differentiate this combined congenital lung lesion from other thoracic pathology in children.

Thoracic Multidetector Computed Tomography Findings of Dedicator of Cytokinesis 8 Deficiency in Children.

PURPOSE: To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of dedicator of cytokinesis 8 (DOCK8) deficiency, a rare autosomal recessive form of hyperimmunoglobulin E syndrome, in children. MATERIALS AND METHODS: All pediatric patients (age 18 y and below) with a known diagnosis of DOCK8 deficiency based on genetic testing who underwent thoracic MDCT studies from November 2004 to November 2020 were included. Two pediatric radiologists independently evaluated MDCT studies for the presence of thoracic abnormalities in the lung [ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, and bronchiectasis], pleura (pleural effusion and pneumothorax), and mediastinum (lymphadenopathy). When a lung abnormality was present, laterality, distribution (upper, middle, and lower lung zone), and extent were also evaluated. When a pleural abnormality was identified, laterality and size of the abnormality were also assessed. When mediastinal lymphadenopathy was present, its location and size were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics. RESULTS: In all, 17 thoracic MDCT studies from 17 individual pediatric patients [5 males (29%) and 12 females (71%); mean age: 7.4 y; SD: 3.7; range: 1 to 13 y] comprised the final study population. Among 17 thoracic MDCT studies, 11 studies (65%) were performed with intravenous contrast (IV) and the remaining 6 MDCT studies (35%) were obtained without IV contrast. Bilateral bronchiectasis (11/17; 65%) with a middle lung zone predominance (8/11; 73%) was the most frequently detected lung abnormality, followed by GGO in 9/17 patients (53%). Among 11 contrast-enhanced MDCT studies, the majority (9 patients, 82%) had mediastinal lymphadenopathy. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.90). CONCLUSION: Children with DOCK8 deficiency have characteristic thoracic MDCT findings, including bilateral bronchiectasis with a middle lung zone predominance, GGO, and mediastinal lymphadenopathy. When these characteristic thoracic MDCT findings are detected, although rare, DOCK8 deficiency should be considered as a possible underlying diagnosis in the pediatric population.

Thoracic Multidetector Computed Tomography Evaluation of Inflammatory Myofibroblastic Tumor of the Lung in Pediatric Patients in the Era of Modern Diagnosis.

PURPOSE: The purpose of this study was to investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven inflammatory myofibroblastic tumor (IMT) of the lung in children in the era of modern understanding based on refined pathologic diagnosis. MATERIALS AND METHODS: All pediatric patients (age 18 y and above) with a known pathologic diagnosis of IMT of the lung who underwent thoracic MDCT studies from May 2008 to December 2020 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung (nodule, mass, cyst, ground-glass opacity, consolidation), pleura (pleural effusion, pneumothorax), and mediastinum and hilum (lymphadenopathy). When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), location (laterality, lobar distribution, and intraparenchymal vs. pleural-based), borders (well-circumscribed vs. ill-defined), the presence and type of associated calcification (punctate, dense, curvilinear, or flocculent), the presence of associated cavitation, contrast enhancement pattern (homogeneous, heterogenous, central, or peripheral), and other associated findings (neural foramen involvement, anomalous vessels, mass effect, and invasion of adjacent thoracic structures) were also evaluated. Interobserver agreement between 2 independent reviewers was evaluated with κ statistics. RESULTS: In all, 12 thoracic MDCT studies from 12 individual pediatric patients (5 males [42%] and 7 females [58%]; mean age: 9.9 y; SD: 4.4 y; range: 2 to 16 y) comprised the final study population. All 12 thoracic MDCT studies (100%) were performed with intravenous contrast. The most frequent MDCT finding of IMT of the lung in children is a solitary (92%), pleural-based (83%), well-circumscribed (100%), solid (92%) mass with heterogenous contrast enhancement (100%), often with dense calcification (50%), which occurred in both lungs and all lobes with similar frequency. No pleural abnormality (pleural effusion, pneumothorax) or mediastinal abnormality (lymphadenopathy) was detected. In addition, although mass effect on adjacent thoracic structures was frequently seen (42%), no invasion, neural foramen involvement, or associated anomalous vessels was identified. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.95). CONCLUSIONS: IMT of the lung in children typically presents as a solitary, pleural-based, well-circumscribed, solid mass with heterogenous contrast enhancement, often with dense calcification, without significant laterality or lobar preference. In addition, pleural or mediastinal abnormalities are characteristically absent. These notable MDCT attributes of IMT of the lung are an important and novel finding, with great potential to help differentiate pediatric IMT of the lung from other thoracic masses in children.

Thoracic Multidetector Computed Tomography Angiography of Primary Pulmonary Vein Stenosis in Children: Evaluation of Characteristic Extravascular Findings.

PURPOSE: The purpose of this study was to investigate the extravascular thoracic multidetector computed tomography (MDCT) angiography findings of pediatric primary pulmonary vein stenosis (PVS) by comparing extravascular thoracic MDCT angiography findings in children with and without PVS. MATERIALS AND METHODS: All pediatric patients (age 18 y and below) with a known diagnosis of primary PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from July 2006 to December 2020 were included. A comparison group, comprised of age-matched and sex-matched pediatric patients without PVS who underwent thoracic MDCT angiography studies during the same study period, was also generated. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung (ground-glass opacity [GGO], consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis), pleura (pleural thickening, pleural effusion and pneumothorax), and mediastinum (lymphadenopathy and mass). When a thoracic abnormality was identified, the location and distribution of the abnormality (in relation to the location of PVS) were also evaluated. Extravascular thoracic MDCT angiography findings of pediatric patients with and without primary PVS were compared. Interobserver agreement between the 2 independent reviewers was evaluated with κ statistics. RESULTS: The study group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients with primary PVS (8 males [53%] and 7 females [47%]; mean age: 10.9 mo; SD: 11.7 mo; range: 1 to 48 mo). The comparison group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients without PVS (8 males [53%] and 7 females [47%]; mean age: 10.2 mo; SD: 11.5 mo; range: 1 to 48 mo). In children with primary PVS, the characteristic extravascular thoracic MDCT angiography findings were GGO (14/15; 93%), septal thickening (5/15; 33%), pleural thickening (14/15; 93%), and ill-defined, mildly heterogeneously enhancing, noncalcified soft tissue mass (14/15; 93%) following the contours of PVS in the mediastinum. There was excellent interobserver κ agreement between 2 independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (κ=0.99 for the study group and κ=0.98 for the comparison group). CONCLUSIONS: Children with primary PVS have characteristic extravascular thoracic MDCT angiography findings. In the lungs and pleura, GGO, septal thickening, and pleural thickening are common findings. Importantly, in the mediastinum, the presence of a mildly heterogeneously enhancing, noncalcified soft tissue mass in the distribution of PVS is a novel characteristic thoracic MDCT angiography finding unique to pediatric primary PVS. When this constellation of extravascular thoracic MDCT angiography findings is detected, although rare, primary PVS should be considered as a possible underlying diagnosis, especially in symptomatic children.

Extravascular MDCT Findings of Pulmonary Vein Stenosis in Children with Cardiac Septal Defect.

Purpose: To retrospectively investigate the extravascular thoracic MDCT angiography findings of pulmonary vein stenosis (PVS) in children with a cardiac septal defect. Materials and Methods: Pediatric patients (age ≤ 18 years) with cardiac septal defect and PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from April 2009 to April 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in: (1) lung and airway (ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis); (2) pleura (pleural thickening, pleural effusion, and pneumothorax); and (3) mediastinum (mass and lymphadenopathy). Interobserver agreement between the two independent pediatric radiology reviewers was evaluated with kappa statistics. Results: The final study group consisted of 20 thoracic MDCT angiography studies from 20 consecutive individual pediatric patients (13 males (65%) and 7 females (35%); mean age: 7.5 months; SD: 12.7; range: 2 days to 7 months) with cardiac septal defect and PVS. The characteristic extravascular thoracic MDCT angiography findings were GGO (18/20; 90%), septal thickening (9/20; 45%), pleural thickening (16/20; 80%), and ill-defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (9/20; 45%) following the contours of PVS in the mediastinum. There was a high interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: PVS in children with a cardiac septal defect has a characteristic extravascular thoracic MDCT angiography finding. In the lungs and pleura, GGO, septal thickening, and pleural thickening are frequently seen in children with cardiac septal defect and PVS. In the mediastinum, a mildly heterogeneously enhancing, non-calcified soft tissue mass in the distribution of PVS in the mediastinum is seen in close to half of the pediatric patients with cardiac septal defect and PVS.

Secondary Pulmonary Vein Stenosis Due to Total Anomalous Pulmonary Venous Connection Repair in Children: Extravascular MDCT Findings.

PURPOSE: To evaluate extravascular findings on thoracic MDCT angiography in secondary pulmonary vein stenosis (PVS) due to total anomalous pulmonary venous connection (TAPVC) repair in children. MATERIALS AND METHODS: All patients aged ≤18 years with a known diagnosis of secondary PVS after TAPVC repair, confirmed by echocardiography, conventional angiography, and/or surgery, who underwent thoracic MDCT angiography studies between July 2008 and April 2021 were included. Two pediatric radiologists independently examined MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung, pleura, and mediastinum. The location and distribution of each abnormality (in relation to the location of PVS) were also evaluated. Interobserver agreement between the two independent pediatric radiology reviewers was studied using kappa statistics. RESULTS: The study group consisted of 20 consecutive pediatric patients (17 males, 3 females) with secondary PVS due to TAPVC repair. Age ranged from 2 months to 8 years (mean, 16.1 months). In children with secondary PVS due to TAPVC repair, the characteristic extravascular thoracic MDCT angiography findings were ground-glass opacity (19/20; 95%), septal thickening (7/20; 35%), pleural thickening (17/20; 85%), and a poorly defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (17/20; 85%) which followed the contours of affected pulmonary veins outside the lung. There was excellent interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). CONCLUSION: Our study characterizes the extravascular thoracic MDCT angiography findings in secondary pediatric PVS due to TAPVC repair. In the lungs and pleura, ground-glass opacity, interlobular septal thickening, and pleural thickening are common findings. Importantly, the presence of a mildly heterogeneously enhancing, non-calcified mediastinal soft tissue mass in the distribution of the PVS is a novel characteristic thoracic MDCT angiography finding seen in pediatric secondary PVS due to TAPVC repair.

Quenching to fix metastable states in models of prebiotic chemistry.

For prebiotic chemistry to succeed in producing a starting metastable, autocatalytic and reproducing system subject to evolutionary selection it must satisfy at least two apparently contradictory requirements: Because such systems are rare, a search among vast numbers of molecular combinations must take place naturally, requiring rapid rearrangement and breaking of covalent bonds. But once a relevant system is found, such rapid disruption and rearrangement would be very likely to destroy the system before much evolution could take place. In this paper we explore the possibility, using a model developed previously, that the search process could occur under different environmental conditions than the subsequent fixation and growth of a lifelike chemical system. We use the example of a rapid change in temperature to illustrate the effect and refer to the rapid change as a "quench"borrowing terminology from study of the physics and chemistry of glass formation. The model study shows that interrupting a high-temperature nonequilibrium state with a rapid quench to lower temperatures can substantially increase the probability of producing a chemical state with lifelike characteristics of nonequilibrium metastability, internal dynamics and exponential population growth in time. Previously published data on the length distributions of proteomes of prokaryotes may be consistent with such an idea and suggest a prebiotic high-temperature "search" phase near the boiling point of water. A rapid change in pH could have a similar effect. We discuss possible scenarios on early Earth which might have allowed frequent quenches of the sort considered here to have occurred. The models show a strong dependence of the effect on the number of chemical monomers available for bond formation.

Passive smoking and risk of oesophageal and gastric adenocarcinomas.

Few studies have examined the association between passive smoking and the risk of oesophageal and gastric adenocarcinomas. In a population-based case-control study with 2474 participants in Los Angeles County, there was no evidence that passive smoking had any appreciable effect on oesophageal or gastric adenocarcinomas.