METHODS: Anatomical MRI and structural DTI were performed cross-sectionally on 26 normal children (newborn to 48 months old), using 1.5-T MRI. The automated processing pipeline was implemented to convert diffusion-weighted images into the NIfTI format. DTI-TK software was used to register the processed images to the ICBM DTI-81 atlas, while AFNI software was used for automated atlas-based volumes of interest (VOIs) and statistical value extraction.
RESULTS: DTI exhibited consistent grey-white matter contrast. Triphasic temporal variation of the FA and MD values was noted, with FA increasing and MD decreasing rapidly early in the first 12 months. The second phase lasted 12-24 months during which the rate of FA and MD changes was reduced. After 24 months, the FA and MD values plateaued.
CONCLUSION: DTI is a superior technique to conventional MR imaging in depicting WM maturation. The use of the automated processing pipeline provides a reliable environment for quantitative analysis of high-throughput DTI data.
KEY POINTS: Diffusion tensor imaging outperforms conventional MRI in depicting white matter maturation. • DTI will become an important clinical tool for diagnosing paediatric neurological diseases. • DTI appears especially helpful for developmental abnormalities, tumours and white matter disease. • An automated processing pipeline assists quantitative analysis of high throughput DTI data.
METHODS: This is a retrospective study done in neonates and infants up to 3 months of age with duct-dependent pulmonary circulation who underwent DS from January 2014 to December 2015. Post-stenting PA growth, surgical outcomes of PA reconstruction, post-surgical re-interventions, morbidity and mortality were analysed.
RESULTS: During the study period, 46 patients underwent successful DS, of whom 38 underwent presurgery catheterization and definite surgery. There was significant growth of PAs in these patients. Biventricular repair was done in 31 patients while 7 had univentricular palliation. Left PA augmentation was required in 13 patients, and 10 required central PA augmentation during surgery. The mean follow-up period post-surgery was 4.5 ± 1.5 years. No significant postoperative complications were seen. No early or follow-up post-surgery mortality was seen. Four patients required re-interventions in the form of left PA stenting based on the echocardiography or computed tomography evidence of significant stenosis.
CONCLUSIONS: DS provides good short-term palliation and the growth of PAs. However, a significant number of stented patients require reparative procedure on PAs at the time of surgical intervention. Acquired changes in the PAs following DS may be the reason for reintervention following PA reconstruction.
CONCLUSIONS: Open MM fracture with bone and soft tissue loss is rare. It is feasible to treat this injury with a novel surgical reconstruction technique involving autogenous bicortical iliac bone graft and radial forearm free flap.
RESULTS: A novel α-amylase (AmyA1) containing an open reading frame of 1482 bp was cloned from Antarctic psychrotolerant fungus G. pannorum and then expressed in the newly constructed Aspergillus oryzae system. The purified recombinant AmyA1 was approximate 52 kDa. AmyA1 was optimally active at pH 5.0 and 40 °C, and retained over 20% of maximal activity at 0-20 °C. The K m and V max values toward soluble starch were 2.51 mg/mL and 8.24 × 10-2 mg/(mL min) respectively, with specific activity of 12.8 × 103 U/mg. AmyA1 presented broad substrate specificity, and the main hydrolysis products were glucose, maltose, and maltotetraose. The influence of AmyA1 on the quality of bread was further investigated. The application study shows a 26% increase in specific volume, 14.5% increase in cohesiveness and 14.1% decrease in gumminess in comparison with the control. AmyA1 was immobilized on magnetic nanoparticles and characterized. The immobilized enzyme showed improved thermostability and enhanced pH tolerance under neutral conditions. Also, magnetically immobilized AmyA1 can be easily recovered and reused for maximum utilization.
CONCLUSIONS: A novel α-amylase (AmyA1) from Antarctic psychrotolerant fungus was cloned, heterologous expression in Aspergillus oryzae, and characterized. The detailed report of the enzymatic properties of AmyA1 gives new insights into fungal cold-adapted amylase. Application study showed potential value of AmyA1 in the food and starch fields. In addition, AmyA1 was immobilized on magnetic nanoparticles and characterized. The improved stability and longer service life of AmyA1 could potentially benefit industrial applications.