Processing of SiO2 protective layer using HMDS precursor by combustion CVD.

Hexamethyldisilazane (HMDS, [(CH3)3Si]2NH) was used as a precursor to form SiO2 protective coatings on IN738LC alloys by combustion chemical vapor deposition (CCVD). SEM and XPS showed that the processed coatings were composed mainly of SiO2. The amount of HMDS had the largest effect on the size of the SiO2 agglomerates and the thickness of the deposited coatings. The specimens coated with SiO2 using the 0.05 mol/l HMDS solution showed a significantly higher temperature oxidation resistance than those deposited under other conditions.

Change of coronary artery indices according to coronary dominance pattern in early childhood.

PURPOSE: Coronary arterial lesion assessment in children can be difficult, depending on the coronary dominance pattern. Although it is easier to determine coronary dominance with echocardiography in children than in adults, it is still difficult. This study aimed to examine the coronary dominance pattern according to the objective coronary artery (CA) indices. METHODS: The CA diameter, aortic valve annulus, and abdominal aorta of 69 children without any cardiovascular disease were measured with cross-sectional echocardiography at Chungnam National University Hospital. To evaluate the coronary dominance pattern, echocardiography was primarily used; additionally, coronary computed tomographic angiography or coronary angiography (CAG). Coronary dominance was determined according to the status of the CA that gives rise to the posterior descending artery. RESULTS: The mean age was 4.02±2.78 years, and the mean body surface area (BSA) was 0.70±0.22 m2 . Right dominance was present in 78% and left in 22% of the subjects. In those with left dominance, the CA to aortic valve annulus diameter ratio was 0.125±0.021 in the right coronary artery (RCA) and 0.255±0.032 in the left coronary artery (LCA). In those with right dominance, the corresponding ratio was 0.168±0.028 in the RCA and 0.216±0.030 in the LCA (P<0.05). Significant differences were also found in the diametric ratios of the CA to BSA and abdominal aorta (P<0.05). CONCLUSION: The CA indices showed significant difference according to the coronary dominance pattern in early childhood. It is possible to indirectly determine the coronary dominance pattern with the CA indices in children using echocardiography. The accuracy of coronary artery lesion diagnosis can be improved by taking coronary dominance into account.

Serum and tear levels of nerve growth factor in diabetic retinopathy patients.

PURPOSE: To measure serum and tear nerve growth factor (NGF) concentrations in diabetic retinopathy (DR) patients to determine whether the NGF correlated with parameters associated with DR. DESIGN: Cross-sectional comparative study. METHODS: The study enrolled 254 DR patients and 71 nondiabetic controls. Patient demographic characteristics and diabetic parameters, including blood sugar levels, HbA1c, liver and renal function, were evaluated in two separate university hospitals. Serum and tear NGF concentrations and the ratio of NGF to total protein (TP) in serum and tear fluid were determined. RESULTS: Serum and tear NGF levels were found to be higher in proliferative diabetic retinopathy (PDR) patients (98.7+/-12.1 ng/ml in serum, 45.6+/-6.3 ng/ml in tear) than in nondiabetic controls (18.5+/-6.1 ng/ml in serum and 8.3+/-4.7 ng/ml in tear) and nonproliferative diabetic retinopathy (NPDR) patients (26.6+/-5.1 ng/ml in serum and 8.6+/-4.2 ng/ml in tear; p<.001 for both serum and tear differences). Similarly, NGF levels were higher in PDR patients than in controls and NPDR patients after adjusting for possible confounding factors such as age, gender, serum blood urea nitrogen, creatinine, and diabetic parameters. In addition, the NGF-to-TP ratio for both serum and tear fluid was higher in the PDR group compared with the control and NPDR groups. NGF levels correlated well with diabetes duration, HbA1c, and blood sugar levels and diabetic nephropathy. CONCLUSIONS: NGF concentration may be a good parameter for evaluating DR status. In addition, serum and tear NGF concentrations correlated strongly, indicating that tear fluid assays may offer an effective, accurate, and noninvasive option for NGF measurement.

Outcomes of 6 hour part-time occlusion treatment combined with near activities for unilateral amblyopia.

PURPOSE: To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia. METHODS: Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate. RESULTS: At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035). CONCLUSIONS: Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Relationship between the retinal thickness analyzer and the GDx VCC scanning laser polarimeter, Stratus OCT optical coherence tomograph, and Heidelberg retina tomograph II confocal scanning laser ophthalmoscopy.

PURPOSE: To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). METHODS: Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. RESULTS: Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). CONCLUSIONS: Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.

Idiopathic hypereosinophilia is clonal disorder? Clonality identified by targeted sequencing.

Idiopathic hypereosinophilia (IHE)/idiopathic hypereosinophilic syndrome (IHES) has been defined by a persistent elevation of the blood eosinophil count exceeding 1.5×103/µL, without evidence of reactive or clonal causes. While T-cell clonality assessment has been recommended for unexplained hypereosinophilia, this approach is not often applied to routine practice in the clinic. We hypothesized that the clonality would exist in a subset of IHE/IHES patients. We aimed to investigate the candidate mutations and T-cell clonality in IHE/IHES and to explore the role of mutations in eosinophil proliferation. We performed targeted capture sequencing for 88 genes using next-generation sequencing, T-cell receptor (TCR) gene rearrangement assays, and pathway network analysis in relation to eosinophil proliferation. By targeted sequencing, 140 variants in 59 genes were identified. Sixteen out of 30 patients (53.3%) harbored at least one candidate mutation. The most frequently affected genes were NOTCH1 (26.7%), SCRIB and STAG2 (16.7%), and SH2B3 (13.3%). Network analysis revealed that our 21 candidate genes (BIRC3, BRD4, CSF3R, DNMT3A, EGR2, EZH2, FAT4, FLT3, GATA2, IKZF, JAK2, MAPK1, MPL, NF1, NOTCH1, PTEN, RB1, RUNX1, TET2, TP53 and WT1) are functionally linked to the eosinophilopoietic pathway. Among the 21 candidate genes, five genes (MAPK1, RUNX1, GATA2, NOTCH1 and TP53) with the highest number of linkages were considered major genes. A TCR assay revealed that four patients (13.3%) had a clonal TCR rearrangement. NOTCH1 was the most frequently mutated gene and was shown to be a common node for eosinophilopoiesis in our network analysis, while the possibility of hidden T cell malignancy was indwelling in the presence of NOTCH1 mutation, though not revealed by aberrant T cell study. Collectively, these results provide new evidence that mutations affecting eosinophilopoiesis underlie a subset of IHE/IHES, and the candidate genes are inferred to act their potential roles in the eosinophilopoietic pathway.

Reproducibility of peripapillary retinal nerve fiber layer thickness measured by spectral domain optical coherence tomography in pseudophakic eyes.

PURPOSE: To assess the reproducibility of circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurement (measurement agreement) and its color-coded classification (classification agreement) by Cirrus spectral domain optical coherence tomography (OCT) in pseudophakic eyes. METHODS: Two-hundred five participants having glaucoma or glaucoma suspected eyes underwent two repeated Cirrus OCT scans to measure cpRNFL thickness (optic disc cube 200 × 200). After classifying participants into three different groups according to their lens status (clear media, cataract, and pseudophakic), values of intra-class coefficient (ICC), coefficient of variance, and test-retest variability were compared between groups for average retinal nerve fiber layer (RNFL) thicknesses and that corresponding to four quadrant maps. Linear weighted kappa coefficients were calculated as indicators of agreement of color code classification in each group. RESULTS: ICC values were all excellent (generally defined as 0.75 to 1.00) for the average and quadrant RNFL thicknesses in all three groups. ICC values of the clear media group tended to be higher than those in the cataract and pseudophakic groups for all quadrants and average thickness. Especially in the superior and nasal quadrants, the ICC value of the cataract group was significantly lower than that of the clear media and pseudophakic groups. For average RNFL thickness, classification agreement (kappa) in three groups did not show a statistically significant difference. For quadrant maps, classification agreement (kappa) in the clear media group was higher than those in the other two groups. CONCLUSIONS: Agreement of cpRNFL measurement and its color code classification between two repeated Cirrus OCT scans in pseudophakic eyes was as good as that in eyes with clear crystalline lens. More studies are required to ascertain the effect of lens status on the reproducibility of Cirrus OCT according to different stages of glaucoma patients.

Multivessel thromboembolism associated with dysfunction of protein s.

Protein S is a vitamin K-dependent coagulation factor that acts as an anticoagulant. Deficiency of protein S increases the risk of thromboembolic events. We report a case of isolated protein S deficiency in a 39-year-old woman suffering arterial occlusion in both lower legs. She underwent a surgical procedure using thrombectomy and balloon angioplasty of her left lower extremity. Later, she had right trans-tibial amputation because of the reperfusion injury. Throughout the evaluation of thromboembolic events, we diagnosed a large thrombus in the right atrium and an asymptomatic pulmonary thromboembolism. The patient was successfully treated with right atrial thrombectomy and systemic anticoagulation. Careful evaluation for protein S levels may be necessary in patients with arterial thromboembolic events, especially young adults.