Synthesis and Characterization of Vanillin-Based π-Conjugated Polyazomethines and Their Oligomer Model Compounds.

The synthesis of π-conjugated polymers via an environmentally friendly procedure is generally challenging. Herein, we describe the synthesis of divanillin-based polyazomethines, which are derived from a potentially bio-based monomer. The polymerization is performed in 5 min under microwave irradiation without any metallic catalyst, with water as the only by-product. The vanillin-based polyazomethines were characterized by SEC, TGA, and UV-Vis spectroscopy. Model compounds were designed and characterized by X-ray diffraction and UV-Vis spectroscopy. The structure/properties study of vanillin-based azomethines used as models allowed us to unequivocally confirm the E configuration and to highlight the cross-conjugated nature of divanillin-based polymers.

Simulating Solvation and Acidity in Complex Mixtures with First-Principles Accuracy: The Case of CH3SO3H and H2O2 in Phenol.

We present a generally applicable computational framework for the efficient and accurate characterization of molecular structural patterns and acid properties in an explicit solvent using H2O2 and CH3SO3H in phenol as an example. To address the challenges posed by the complexity of the problem, we resort to a set of data-driven methods and enhanced sampling algorithms. The synergistic application of these techniques makes the first-principle estimation of the chemical properties feasible without renouncing to the use of explicit solvation, involving extensive statistical sampling. Ensembles of neural network (NN) potentials are trained on a set of configurations carefully selected out of preliminary simulations performed at a low-cost density functional tight-binding (DFTB) level. The energy and forces of these configurations are then recomputed at the hybrid density functional theory (DFT) level and used to train the neural networks. The stability of the NN model is enhanced by using DFTB energetics as a baseline, but the efficiency of the direct NN (i.e., baseline-free) is exploited via a multiple-time-step integrator. The neural network potentials are combined with enhanced sampling techniques, such as replica exchange and metadynamics, and used to characterize the relevant protonated species and dominant noncovalent interactions in the mixture, also considering nuclear quantum effects.

Neonatal congenital lung tumors - the importance of mid-second-trimester ultrasound as a diagnostic clue.

BACKGROUND: The differential diagnosis for primary lung masses in neonates includes a variety of developmental abnormalities; it also consists of the much rarer congenital primary lung tumors: cystic pleuropulmonary blastoma (cystic PPB), fetal lung interstitial tumor (FLIT), congenital peribronchial myofibroblastic tumor (CPMT), and congenital fibrosarcoma. Radiologic differentiation between malformations and tumors is often very challenging. OBJECTIVE: The objective was to establish distinctive features between developmental pulmonary abnormalities and primary lung tumors. MATERIALS AND METHODS: We conducted a retrospective study of 135 congenital lung lesions at a university mother and child center over a period of 10 years (2005-2015). During this time, we noted four tumors (two cystic PPBs and two FLITs) and 131 malformations. We recorded the following parameters: timing of conspicuity in utero (mid-second trimester, third trimester, or not seen prenatally), presence of symptoms at birth, prenatal and perinatal radiologic findings, and either histological diagnoses by pathology or follow-up imaging in non-operated cases. RESULTS: All lesions except the four tumors were detected during mid-second-trimester ultrasound. In none of the tumors was any pulmonary abnormality found on the mid-second-trimester sonogram, contrary to the developmental pulmonary abnormalities. CONCLUSION: The timing of conspicuity in utero appears to be a key feature for the differentiation between malformations and tumors. Lesions that were not visible at the mid-second-trimester ultrasound should be considered as tumor. A cystic lung lesion in the context of a normal mid-second-trimester ultrasound is highly suggestive of a cystic PPB. Differentiating the types of solid congenital lung tumors based upon imaging features is not yet feasible.

Tumor hepático con vías biliares normales en un paciente con síndrome de Alagille: a propósito de un caso / Liver mass containing normal bile ducts in an Alagille patient: a case report

En este artículo se informa el caso de un paciente con síndrome de Alagille, que desarrolló una lesión de crecimiento rápido en el lóbulo caudado del hígado cirrótico. Se realizó el seguimiento riguroso del tumor aunque, desde el punto de vista radiológico, no parecía ser maligno. En el estudio por resonancia magnética (RM), no se observó ningún criterio diagnóstico de carcinoma hepatocelular; no obstante, se realizó una biopsia de la lesión y del hígado debido al rápido crecimiento del tumor. Los resultados del informe anatomopatológico indicaron desarrollo normal de los conductos biliares en el tumor y escasez de conductos biliares en la segunda muestra del hígado. Describiremos este caso y propondremos una interpretación de estos resultados.

This manuscript reports a case of a patient with Alagille syndrome who developed a rapidly growing lesion in the caudate segment of his cirrhotic liver. This mass was closely monitored but did not seem malignant from a radiological point of view. An MRI showed no criteria in favour of a hepatocarcinoma, however, the rapid growth lead to a biopsy of both the lesion and the cirrhotic liver. The pathology results indicated normal development of the bile ducts in the mass and paucity of the biliary ducts in the second liver specimen. We will describe this case and propose an interpretation of these findings.

[Liver mass containing normal bile ducts in an Alagille patient: a case report]. / Tumor hepático con vías biliares normales en un paciente con síndrome de Alagille: a propósito de un caso.

This manuscript reports a case of a patient with Alagille syndrome who developed a rapidly growing lesion in the caudate segment of his cirrhotic liver. This mass was closely monitored but did not seem malignant from a radiological point of view. An MRI showed no criteria in favour of a hepatocarcinoma, however, the rapid growth lead to a biopsy of both the lesion and the cirrhotic liver. The pathology results indicated normal development of the bile ducts in the mass and paucity of the biliary ducts in the second liver specimen. We will describe this case and propose an interpretation of these findings.

Prenatal ultrasound screening of congenital heart disease in the general population: general concepts, guidelines, differential diagnoses.

Congenital heart diseases (CHDs) carry a high prevalence rate in the general population (0.8%-1%). Most fetal CHDs occur in patients without any risk factors. The prenatal recognition of CHD has major impacts on the pregnancy and its outcome. The aforementioned data justify prenatal ultrasound (US) screening of CHD in the general low-risk population. As demonstrated in the literature, the application of an extended basic US cardiac examination improves the detection of CHD, in particular the conotruncal anomalies. The stepwise method suggested for fetal heart US screening during the mid-second trimester sonogram is based on 4 routine axial views of heart and great vessels: (1) a transverse view of the superior abdomen, (2) a 4-chamber view, (3) a 3-vessel view, and (4) a transverse view of the aortic arch. This protocol can be obtained rapidly because these scans are easy to perform. Despite the fact that the sequential segmental approach universally used in the postnatal diagnosis of CHD is not specifically addressed here, the detected anomalies can be categorized according to these views, and a short differential diagnosis proposed. Abnormal cardiac and/or vascular landmarks shown on these key scans should lead to a referral in the fetal cardiac center for a more precise evaluation, as well as for counseling.

Restricting indications for sinonasal computed tomography in children with cystic fibrosis.

OBJECTIVES To evaluate whether a low rate of exposure to sinonasal computed tomographic (CT) scans can be achieved when strict criteria are applied for their use in children with cystic fibrosis (CF) and to emphasize the importance of limiting radiation exposure in the context of the current longer life expectancy in this group of patients. DESIGN Retrospective chart review. SETTING Tertiary care children's hospital. PATIENTS The study included 277 children who were regularly followed up in the CF clinic in the last 11 years (mean duration of follow up, 7.87 years), 33 of whom underwent sinonasal CT. MAIN OUTCOME MEASURES Indications used for scanning, health professional (ear, nose, and throat specialist or pulmonologist) ordering the test, eventual modifications of ongoing treatment according to CT results, and time lapse between CT scanning and surgery. RESULTS Of 277 children with CF, 33 (12%) underwent a total of 39 sinonasal CT scans during the follow-up period (0.018 scans per patient per year of follow-up). Twenty-nine of the CT scans (74% of all cases, 90% of CT scans ordered by the ear, nose, and throat surgeon) were performed in the preoperative context and demonstrated the extent of the polypoid disease whenever present (26 cases [90%]) and the cause of nasal obstruction (20 cases [69%]). The mean period between the scanning and the surgery was 57 days (range, 0.10-173 days). Computed tomographic scans that were not meant for preoperative planning were performed in 10 cases (26%). The indications were disease evaluation (10%), ruling out a mucocele (5%); pre-lung transplantation status (5%), ruling out an intraorbital complication (3%); and headache investigation (3%). The results of the scans did not modify the management of the disease in those patients. CONCLUSIONS With the use of stringent criteria, it is possible to achieve a low rate of exposure to sinonasal CT scans in the population of children with CF. The main indication should be the preoperative planning regarding anatomy, extent of disease, and sites of nasal obstruction. The use of CT scans for disease evaluation does not seem to appreciably modify the treatment course and could be avoided.

Questioning the legitimacy of rigid bronchoscopy as a tool for establishing the diagnosis of a bronchial foreign body.

OBJECTIVES: Rigid bronchoscopy (RB) is the principal method used for the extraction of a tracheo-bronchial foreign body (FB), but its use as a diagnostic tool implies a certain rate of negative exams, exposing the child to the risk of procedure and anesthesia-related complications. Technological progress has improved the accuracy and availability of non-invasive modalities, such as CT scan and fluoroscopy. Our aim is to review our experience in the routine use of bronchoscopy for a suspected FB aspiration, and evaluate the adequacy of our current attitude in light of these alternatives. METHODS: We performed a retrospective review of cases where bronchoscopy was used in the management of a suspected airway FB, and analysis of the correlation between the clinical and radiological data and the bronchoscopy's results. In addition we reviewed the literature concerning the use of RB and alternative means of diagnosis such as CT scan, fluoroscopy and flexible bronchoscopy. RESULTS: Thirty-two patients underwent bronchoscopy to rule out a FB aspiration under general anesthesia. No FB was found in 8 cases (25%). Cough and a history of choking were the most sensitive parameters (sensitivity 100% and 80% respectively), but had a low specificity. Stridor was the most specific sign (88% specificity), but was not sensitive. Chest radiography had 25% sensitivity, and 62.5% specificity. Flexible bronchoscopy changed the management in 22% of cases, sparing RB. CONCLUSIONS: Basing the decision to perform RB solely on the clinical findings and chest radiography entails a 25% rate or more of negative exams. CT scan appears to be the most accurate non-invasive tool for ruling out the presence of a FB but its use cannot be systematic due to its complexity and the risks of exposure to radiation. Digital substraction fluoroscopy is a safe and simple mean to confirm the presence of air trapping generated by a bronchial obstruction, but it is not sensitive enough to definitively rule out a FB. We propose a stepwise approach using fluoroscopy or possibly flexible bronchoscopy under sedation, in order to reduce the number of negative RBs while restricting the use of the CT scan.

Antenatal imaging: does the postnatal impact justify the effort?

This review explores what is already understood about antenatal diagnosis of a variety of conditions,including Down syndrome, what progress has been made in this field, the role that imaging plays in the diagnostic pathway and the impact on management of pregnancies and the parental decision process. An overview of future potential developments is also made.

Imaging of biliary disorders in children.

Biliary atresia and related disorders of the biliary tree, such as choledochal cyst, must be considered in the differential diagnosis of prolonged conjugated hyperbilirubinemia in infants and children. Pediatric biliary tract diseases include a variety of entities with a wide range of clinical presentations. Radiology plays an important role in the diagnosis and management of these pathologies. Unrecognized causes of biliary disease, like biliary atresia, can lead to liver transplantation during the first year of life. The aim of this article is to review the imaging of pediatric biliary disorders, including the implications of interventional radiology in some biliary diseases.

Unilateral absence of pulmonary artery in children: bronchovascular anatomy, natural course and effect of treatment on lung growth.

BACKGROUND: Unilateral absence of pulmonary artery (UAPA) is a rare congenital anomaly with few published studies focusing on anatomy and outcome. OBJECTIVE: To assess the bronchovascular anatomy, lung volume and growth in treated and untreated patients with UAPA. MATERIALS AND METHODS: Eighteen children with UAPA (isolated: n = 12; associated with congenital heart disease: n = 6) were retrospectively studied to assess the vascularization and lung segmentation and to appraise lung volume evolution in treated and untreated patients. Age at presentation: 1 day to 6 years; mean follow-up duration 13.6 years. Reperfusion of the affected pulmonary artery was attempted in 10 children (younger than 6 months: n = 7; older than 6 months: n = 3). RESULTS: Bronchovascular lung segmentation was complete in all cases. In children treated before 6 months of age, lung volume normalized in 3 and remained normal in 3, and hypoplasia progression was noted in 1. Hypoplasia persisted in children treated after 6 months of age. In untreated children, lung hypoplasia was unchanged in cases diagnosed after 7 months of age (n = 4) and progressive in cases diagnosed before 3 months (n = 4). CONCLUSION: In UAPA, lung anatomy and volume are normal at birth. Revascularization of the affected pulmonary artery before 6 months of age seems to allow optimal lung growth and prevent postnatal lung hypoplasia and development of collaterals.

Segmental approach to imaging of congenital heart disease.

The segmental approach, which is widely used in the imaging work-up of congenital heart disease, consists of a three-step evaluation of the cardiac anatomy. In step 1, the visceroatrial situs is determined. Visceroatrial situs refers to the position of the atria in relation to the nearby anatomy (including the stomach, liver, spleen, and bronchi). Three different anatomic configurations may be observed: situs solitus (normal), situs inversus (inverted), or situs ambiguus (ambiguous). In step 2, the left- or rightward orientation of the ventricular loop is evaluated, and the positions of the ventricles are identified on the basis of their internal morphologic features. In step 3, the position of the great vessels is determined first, and any abnormalities are noted. Abnormalities in the origin of the great vessels, or conotruncal anomalies, are predominantly of three types: D-transposition (dextrotransposition), L-transposition (levotransposition), and D-malposition with double outlet right ventricle. Next, the relationships between the atria and ventricles and the ventricles and great vessels are determined at two levels: atrioventricular (concordant, discordant, ambiguous, double inlet, absence of right or left connection) and ventriculoarterial (concordant, discordant, double outlet). Last, a search is performed for any associated abnormalities of the cardiac chambers, septa, outflow tract, and great vessels. By executing these steps sequentially during image review, the radiologist can achieve a more accurate interpretation. Multiplanar reconstructions of cross-sectional image data obtained with computed tomography or magnetic resonance imaging are particularly useful for evaluating congenital heart disease.

Follow-up chest X-ray in patients with Kawasaki disease: the significance and clinical application of coronary artery macro-calcification.

Kawasaki disease (KD) related coronary artery (CA) aneurysms may lead to significant and potentially insidious progressive stenosis. It is also well recognized that CA scarring leads to heavy calcification in KD. We intended to correlate the angiographic anomalies associated with coronary calcifications in KD and to evaluate the chronology and the detection rate of KD-related CA calcification on plain chest X-ray. Between 1992 and 2006, 65 CA angiograms were performed in 50 KD patients. Chest fluoroscopies and angiograms were retrospectively reviewed. When angiograms were abnormal, chest X-rays were reviewed by two radiologists blinded to the results of angiograms. CA lesions were identified in 18/50 (36%) patients, including isolated CA aneurysms in 10. All 8 patients who had CA aneurysms associated with stenosis and/or occlusion had CA calcification identifiable on chest X-ray. All significant stenotic lesions were concomitant with calcification. Plain chest X-ray, a simple inexpensive low dose mean, easily identifies KD patients at risk for serious CA stenosis when specific search for CA calcification is pursued. When detected, a closer tracking of coronary artery patency is warranted via other imaging techniques, usually expensive, invasive, requiring sedation in children or exposing to high radiation.

Paratesticular rhabdomyosarcoma presenting as thickening of the tunica vaginalis.

Pediatric paratesticular primary malignant tumors are rare, and most of them correspond to rhabdomyosarcomas (RMS). Paratesticular RMS has a better prognosis than RMS originating in other locations, because of its favorable histology and possible early diagnosis. The diagnosis relies upon the US findings of a paratesticular hypervascular mass in an adequate clinical setting. We report the unusual appearance of an infiltrating RMS tumor in a 3-year-old boy. The tumor presented as thickening of the tunica vaginalis. Atypical US appearance and discordance with clinical features caused suspicion of a tumoral process, allowing early diagnosis and treatment.

Incidence of deep vein thrombosis related to peripherally inserted central catheters in children and adolescents.

BACKGROUND: Peripherally inserted central catheters (PICC) in children and adolescents are being used with increasing frequency. We sought to determine the incidence and characterize risk factors of deep vein thrombosis associated with peripherally inserted central catheters in a pediatric population. METHODS: We conducted a prospective study involving consecutive patients referred to the radiology department of a tertiary care university-affiliated hospital for insertion of a peripherally inserted central catheter. We included patients aged 18 years or less who weighed more than 2.5 kg and had a peripherally inserted central catheter successfully inserted in his or her arm between June 2004 and November 2005. The primary outcome was the occurrence of partial or complete deep vein thrombosis evaluated by clinical examination, ultrasonography and venous angiography. RESULTS: A total of 214 patients (101 girls, 113 boys) were included in the study. Partial or complete deep vein thrombosis occurred in 20 patients, for an incidence of 93.5 per 1000 patients and 3.85 per 1000 catheter-days. Only 1 of the cases was symptomatic. In the univariable analyses, the only variable significantly associated with deep vein thrombosis was the presence of factor II mutation G20210A (odds ratio 7.08, 95% confidence interval 1.11-45.15, p = 0.04), a genetic mutation that increases the risk of a blood clot and that was present in 5 (2.3%) of the 214 patients. INTERPRETATION: The incidence of deep vein thrombosis related to peripherally inserted central catheters in our study was lower than the incidence related to centrally inserted venous catheters described in the pediatric literature (11%-50%).

Pediatric gastrointestinal vascular anomalies: imaging and therapeutic issues.

Vascular anomalies are an uncommon cause of gastrointestinal bleeding. Imaging plays an important role in the diagnosis and therapy of these anomalies. Accurate diagnosis, classification and awareness of associated syndromes are mandatory for applying the appropriate management. In this pictorial essay we review the classification, imaging characteristics and treatment of gastrointestinal vascular anomalies.

Percutaneous drainage of abdominal abscesses in pediatric Crohn's disease.

OBJECTIVE: Crohn's disease is complicated by abscesses in 10-30% of patients during their lifetime. The goal of our study was to illustrate that, besides surgical treatment, percutaneous abscess drainage plays a major role in treating children with Crohn's disease. MATERIALS AND METHODS: This retrospective study included 14 pediatric patients (age range, 12-17 years; median age, 15 years) with proven Crohn's disease. Percutaneous abscess drainage was performed for 15 abdominal or pelvic abscesses or for both abdominal and pelvic abscesses. The abscess was an initial manifestation of Crohn's disease in four patients and complicated well-known disease in 10 patients. Abscesses occurred spontaneously (n = 11), after surgery (n = 3), or after infliximab treatment (n = 1). Their volume ranged from 8 to 442 mL (mean, 113 mL). Fistulas with the bowel were detected in eight cases. RESULTS: Sixteen percutaneous abscess drainages were performed under sonographic or CT guidance (or both) using 6- or 8-French catheters. The procedure was performed with the patient under conscious sedation (n = 14) or anesthesia (n = 2). The duration of the drainage was 1-30 days (mean, 11 days). An enterocutaneous fistula, medically treated with success, was the only complication observed. Complete resolution of the collection was observed in eight abscesses and partial resolution in seven. Resection of the diseased bowel segment with primary anastomosis was possible in 12 patients. In two patients, percutaneous abscess drainage was not followed by surgery. CONCLUSION: Percutaneous abscess drainage is a valuable procedure in pediatric patients with Crohn's disease presenting with pelvic or abdominal abscesses (or both). It improves the general status of the patient and allows a less invasive and easier subsequent surgical procedure. Percutaneous abscess drainage should be performed before definitive treatment.

Recurrent pancreatitis in mitochondrial cytopathy.

Diabetes mellitus and exocrine insufficiency are the commonest pancreatic manifestations of mitochondrial diseases. In contrast, pancreatitis has rarely been described in mitochondrial syndromes. We report on a patient with Kearns-Sayre syndrome and recurrent episodes of acute pancreatitis for which no explanation could be found other than the associated mitochondrial dysfunction. Interestingly, pharmacological disruption of mitochondrial metabolism in various models as well as in patients can cause pancreatitis, further supporting this association. A diagnosis of pancreatitis should be considered in any patients with mitochondrial disease and recurrent abdominal pain.