Validity of the Korean Developmental Screening Test for very-low-birth-weight infants

Purpose The importance of the neurodevelopmental outcomes of very-low-birth-weight (VLBW) infants has been emphasized as their mortality rate has markedly improved. This study aimed to assess the validity of the Korean Developmental Screening Test (K-DST), a developmental screening tool approved by the Korean Society of Pediatrics, for the timely diagnosis of neurodevelopmental delay in VLBW infants. Methods Subjects included VLBW infants enrolled in the Korean Neonatal Network database between January 2012 and December 2014. The collected data were analyzed for sensitivity, specificity, positive predictive value, and negative predictive value (NPV) in the K-DST compared to those in the Bayley Scales of Infant Development-II for VLBW infants. Results A total of 173 patients were enrolled. Their mean gestational age and mean birth weight were 27.5±2.8 weeks and 980.5±272.1 g, respectively. The frequency of failed psychomotor developmental index (PDI) <85 was similar to that in at least one domain of K-DST <1 standard deviation. Failure in more than one K-DST domain compared with a mental developmental index (MDI) <85 showed a sensitivity and NPV of 73.2% and 75.0%, respectively. Failure in more than one K-DST domain compared with PDI <85 showed a sensitivity and NPV of 60.3% and 71.6%, respectively. Each K-DST domain had a stronger correlation with predicting a failing MDI <85 than a failing PDI <85 (P<0.05). Conclusion K-DST could be a useful screening tool for predicting mental developmental delay in VLBW infants and referring them for neurodevelopmental assessments

Effect of Multiple Quantum Well Periods on Structural Properties and Performance of Extended Short-Wavelength Infrared LEDs

We present research on the role of multiple quantum well periods in extended short-wavelength infrared InGaAs/InAsPSb type-I LEDs. The fabricated LEDs consisted of 6, 15, and 30 quantum well periods, and we evaluated the structural properties and device performance through a combination of theoretical simulations and experimental characterization. The strain and energy band offset was precisely controlled by carefully adjusting the composition of the InAsPSb quaternary material, achieving high valence and conduction band offsets of 350 meV and 94 meV, respectively. Our LEDs demonstrated a high degree of relaxation of 94-96 %. Additionally, we discovered that the temperature-dependent dark current characterization attributed to generation-recombination and trap-assign tunneling, with trap-assign tunneling being more dominant at lower current injections. Electroluminescence analysis revealed that the predominant emission mechanism of the LEDs originated from localized exciton and free exciton radiative recombination, which the 30 quantum wells LED exhibited the highest contribution of the localized exciton/free exciton radiative recombination. We observed that increasing the quantum well periods from 6 to 15 led to an increase in the 300 K electroluminescence intensity of the LED. However, extending the quantum well period to 30 resulted in a decline in emission intensity due to the degradation of the epitaxial film quality

Retroperitoneal laparoscopic ureterolithotomy for upper ureter stones

We evaluated the role of retroperitoneal laparoscopic ureterolithotomy (RPLU) for upper ureter stones. Between February 1998 and July 2004, 12 patients (10 men and 2 women) underwent RPLU for upper ureter stones (mean size 18.1 mm, range 10-25). RPLU was carried out in 5 patients as a salvage treatment after failed shock wave lithotripsy (SWL) (3) and both of failed SWL and ureteroscopy (URS) (2), and in 7 patients as primary treatment for large impacted stones. Total 6 of 12 cases were converted to open surgery. The reason of open conversion was failure of locating ureter due to severe adhesion in 5 cases and vascular injury in 1 case. In 6 successful cases, mean operation time, mean estimated blood loss, and mean postoperative hospital stay were respectively 109 min (90-120 min), 50 mL (10-100 mL), 4.6 days (2-7 days). There was no serious postoperative complication except for one patient who showed delayed urinary leakage but was cured with conservative management. Our experience suggested that RPLU was not easy to perform simply because it was indicated mainly in ureter stones with severe adhesion or after failed SWL and/or URS. Nevertheless, it can be considered as a primary procedure before open ureterolithotomy

A Case of Acute Myocardial Infarction Caused by Distal Embolization of a Left Main Coronary Artery Thrombus

Coronary embolism is an uncommon cause of myocardial infarction. A 48-year-old male presented with typical chest pain of an MI. There was no definite ST segment change on electrocardiogram (ECG) and no elevation of myocardial enzymes. Coronary angiography (CAG) revealed occlusion of the distal left anterior descending coronary artery (dLAD), the distal left circumflex coronary artery (dLCX), the diagonal branch (D) and the obtuse marginal branch (OM), with a large filling defect in the left main coronary artery (LMA) that caused the myocardial infarction. We considered the possibility that coronary embolization was caused by the migration of a thrombus in the LMA during CAG. We did balloon angioplasty in the dLAD, dLCX, OM and D and treated the patient with glycoprotein IIb/IIIa receptor antagonist. However, thrombi remained in the dLAD, OM, and dLCX. After 3 days of anti-thrombotic treatment, follow-up CAG revealed only slight resolution of thrombi in the LAD. After triple antiplatelet agent medication for 1 year, a follow-up CAG showed a resolution of the thrombi in all coronary arteries

A Case of Campomelic Dysplasia without Sex Reversal

Campomelic dysplasia (CD; OMIM #114290), a rare form of congenital short-limbed dwarfism, is due to mutations in SOX9, a member of the SOX (SRY-related HMG box) gene family. Multiparous mother at 38 weeks' gestation delivered a 3,272 g baby boy with characteristic phenotypes including bowing of the lower limbs, a narrow thoracic cage, 11 pairs of ribs, hypoplastic scapulae, macrocephaly, flattened supraorbital ridges and nasal bridge, cleft palate, and micrognathia. He underwent a tracheostomy at the age of three months for severe laryngomalacia after a number of repeated hospitalizations due to respiratory problems and died at the age of four months from progressive respiratory failure. He was diagnosed as having CD based on a novel frameshift mutation (p.Gln458ArgfsX12) in the SOX9 gene, the mutation which has not yet been reported in Korea