Two dimensional echocardiographic evaluation of exercise-induced left and right ventricular asynergy: Correlation with thallium scanning

Adequate real time two dimensional echocardiograms were prospectively obtained before and immediately after graded treadmill exercise testing in 41 of 48 patients who underwent cardiac catheterization for suspected coronary artery disease. Findings were correlated with thallium perfusion scans performed 5 to 10 minutes and 3 hours after the same exercise test. Exercise-induced wall motion abnormalities were detected in 19 of 23 patients with significant coronary artery disease and no prior myocardial infarction as well as in all 5 patients with known previous infarction. Three patients with coronary artery disease experienced new isolated right ventricular asynergy with exercise that would have been missed if only the left ventricle had been evaluated. Exercise-induced thallium perfusion defects showed good correlation with exercise-induced asynergy as detected with echocardiography. Two dimensional echocardiography performed immediately after treadmill stress testing is a feasible and rewarding technique in the evaluation of patients suspected to have coronary artery disease.     

Transesophageal Echocardiographic Diagnosis of Right-Sided Aortic Arch

We present the transesophageal echocardiographic findings in two adult patients with right-sided aortic arch: one without dissection and the other with traumatic aortic injury (dissection). In both patients, the branching pattern was the left common carotid artery and then the right common carotid artery, followed by the right and left subclavian arteries. The technique for the diagnosis of this anomaly and the identification of adjacent vascular structures using contrast echocardiography is described. Three-dimensional reconstruction of the aortic arch also was performed in both patients.     

Usefulness of transesophageal three-dimensional echocardiography in the identification of individual segment/scallop prolapse of the mitral valve

We evaluated the potential usefulness of three-dimensional (3D) transesophageal echocardiography (TEE) in assessing individual scallop/segment prolapse in 36 adult patients with mitral valve prolapse (MVP) undergoing surgical correction. Intraoperative 3D TEE correctly identified the location of scallop/segment prolapse in 34 of 36 patients (94%). However, in 6 of these patients 3D TEE images revealed more scallops or segments with prolapse than the surgeon noted intraoperatively. Prolapse of these areas was less prominent and this could possibly explain the lack of correlation with the surgical findings in these patients. In another 2 patients areas of prolapse seen by the surgeon were missed by 3D TEE because some of those scallops/segments could not be well imaged due to image "drop out" and artifacts. Thus, perfect correlation between 3D TEE and surgery was noted in 28 of 36 (78%) patients. Noncoaptation of the MV was also identified in 2 patients. The prolapsed area of posterior (n = 28 observations) and anterior (n = 9 observations) MV leaflets ranged from 1 cm2 to 9 cm2 (mean 3.50 cm2+/- 2.14) and 1.20 cm2 to 5.99 cm2 (mean 3.21 cm2+/- 1.33), respectively. Interobserver and intraobserver agreement for location and area of MVP was excellent (r = 0.97 and r = 0.99, respectively; all P values are <0.0001). In conclusion, 3D TEE is useful in identifying the location of MVP. It may also be potentially useful in assessing the extent of individual scallop/segment prolapse and identifying sites of MV noncoaptation. This information could aid the surgeon in deciding the extent of MV resection.     

ESAT and M-CHAT as screening instruments for autism spectrum disorders at 18 months in the general population: issues of overlap and association with clinical referrals

The Modified Checklist for Autism in Toddlers (M-CHAT) and the Early Screening of Autistic Traits (ESAT) were designed to screen for autism spectrum disorders in very young children. The aim of this study was to explore proportions of children that screened positive on the ESAT or the M-CHAT and to investigate if screening positive on the ESAT and M-CHAT is associated with clinical referral by 18 months and other aspects of children’s development, health, and behavior. In this study, the mothers of 12,948 18-month-old children returned a questionnaire consisting of items from the ESAT and M-CHAT, plus questions about clinical and developmental characteristics. The M-CHAT identified more screen-positive children than the ESAT, but the ESAT was associated with more clinical referrals and tended to identify more children with medical, language, and behavioral problems. A post hoc analysis of combining the two instruments found this to be more effective than the individual instruments alone in identifying children referred to clinical services at 18 months. Further analysis at the level of single items is warranted to improve these screening instruments.     

Hepatopulmonary syndrome associated with nodular regenerative hyperplasia after liver transplantation in a child

HPS is a significant complication of portal hypertension in children with chronic liver disease and is an established indication for LT. It is characterized clinically by the triad of pulmonary vascular dilatation causing hypoxemia in the setting of advanced liver disease. NRH, a cause of non‐cirrhotic portal hypertension, is characterized by diffuse benign transformation of the hepatic parenchyma into small regenerative nodules with minimal or no fibrosis. Development of NRH and HPS in pediatric LT recipients has not been reported, although occasional cases have been reported in adult LT recipients. In this report, we discuss a case of a three‐yr‐old male who developed HPS, two yr after LT. Pulmonary and cardiac causes for hypoxemia were ruled out by appropriate investigations including a chest X ray, echocardiogram, cardiac catheterization, and a CT angiographic study. The diagnosis of HPS was confirmed via bubble echocardiogram that demonstrated intrapulmonary shunting. Open liver biopsy revealed marked NRH. The patient underwent liver retransplantation that resulted in complete reversal of his pulmonary symptoms and normal oxygen saturations within three months after LT.     

Osteocyte death during orthodontic tooth movement in mice

Objective:To investigate the time course of osteocyte death in a mouse model of orthodontic tooth movement (OTM) and its association to the caspase-3 activation pathway and osteoclast formation.Materials and Methods:Twenty-five male wild type CD-1 mice (8–12 weeks old) were loaded with an orthodontic appliance. A spring delivering 10–12 g of force was placed between the right first molar and the incisor to displace the first molar mesially. The contralateral unloaded sides served as the control. The animals were equally divided into five different time points: 6, 12, 24, and 72 hours and 7 days of orthodontic loading. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, caspase-3 immunostaining, and tartrate-resistant acid phosphatase (TRAP) staining was performed on histologic sections of the first molars. The labeling was quantified in osteocytes on the compression side of the alveolar bone at each time point.Results:TUNEL labeling significantly increased at 12, 24, and 72 hours after orthodontic loading; the peak was observed at 24 hours. Elevated caspase-3 labeling was noted at 12, 24, and 72 hours and 7 days after loading, although the increase was not significant. Significant osteoclast formation was initially evident after 72 hours and progressively increased up to 7 days.Conclusions:Osteocyte death during OTM peaks at 24 hours, earlier than initial osteoclast activation. However, only a slight trend for increased caspase-3 activity suggests that other mechanisms might be involved in osteocyte death during OTM.     

Enhanced mechanical properties of hBN–ZrO2 composites and their biological activities on Drosophila melanogaster: synthesis and characterization

In this study, six compositions in the system [x(h-BN)–(100 − x)ZrO₂] (10 ≤ x ≤ 90) were synthesized by a bottom up approach, i.e., the solid-state reaction technique. XRD results showed the formation of a novel and main phase of zirconium oxynitrate ZrO(NO₃)₂ and SEM exhibited mixed morphology of layered and stacked h-BN nanosheets with ZrO₂ grains. The composite sample 10 wt% h-BN + 90 wt% ZrO₂ (10B90Z) showed outstanding mechanical properties for different parameters, i.e., density (3.12 g cm⁻³), Young''s modulus (10.10 GPa), toughness (2.56 MJ m⁻³), and maximum mechanical strength (227.33 MPa). The current study further checked the in vivo toxicity of composite 10B90Z and composite 90B10Z using Drosophila melanogaster. The composite 10B90Z showed less cytotoxicity in this model, while the composite 90B10Z showed higher toxicity in terms of organ development as well as internal damage of the gut mostly at the lower concentrations of 1, 10, and 25 μg mL⁻¹. Altogether, the current study proposes the composite 10B90Z as an ideal compound for applications in biomedical research. This composite 10B90Z displays remarkable mechanical and biological performances, due to which we recommend this composition for various biomedical applications.

In this study, six compositions in the system [x(h-BN)–(100 − x)ZrO₂], (10 ≤ x ≤ 90) were synthesized by a bottom up approach, i.e., the solid-state reaction technique.