Placental Area in the Lower Uterine Segment, Cervical Length, and Clinical Outcome in Pregnancies With Complete Placenta Previa.

BACKGROUND: Complete placenta previa is associated with a higher percentage of adverse clinical outcomes and magnetic resonance imaging (MRI) is widely used in the preoperative examination of patients with placenta previa. PURPOSE: To evaluate the effectiveness of the placental area in the lower uterine segment and cervical length in identifying the adverse maternal-fetal outcomes in women with complete placenta previa. STUDY TYPE: Retrospective. POPULATION: A total of 141 pregnant women (median age, 32; age range, 24-40 years) with complete placenta previa were examined by MRI to evaluate the uteroplacental condition. FIELD STRENGTH/SEQUENCE: A 3 T with T1 -weighted imaging (T1 WI), T2 -weighted imaging (T2 WI), and half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence. ASSESSMENT: The association of the placental area in the lower uterine segment and cervical length measured using MRI with the risk of massive intraoperative hemorrhage (MIH) and maternal-fetal perinatal outcomes were determined. The adverse neonatal outcomes (preterm delivery, respiratory distress syndrome [RDS], admission to neonatal intensive care unit [NICU]) were analyzed in different groups. STATISTICAL TESTS: The t-test, Mann-Whitney U test, Chi-square, Fisher's exact test, and receiver operating characteristic (ROC) curve were used, and a P < 0.05 indicated a statistically significant difference. RESULTS: The mean operation time, intraoperative blood loss, and intraoperative blood transfusing were significantly higher in patients with large placental area and short cervix than in patients with the small placental area and long cervix, respectively. The incidence of adverse neonatal outcomes was significantly higher in the large placenta area group and short cervix group than in the small placenta group area and long cervix group, respectively, such as preterm delivery, RDS, and NICU. By combining placental area with cervical length sensitivity and specificity increased to 93% and 92%, respectively, for the identification of MIH > 2000 mL with area under the receiver operating curve (AUC) 0.941. DATA CONCLUSION: Large placental area and short cervical length may be associated with a high risk of MIH and adverse maternal-fetal perinatal outcomes in patients with complete placenta previa. TECHNICAL EFFICACY STAGE: 2.

[Genetic diagnosis of a Chinese pedigree affected with Alazami syndrome].

OBJECTIVE: To explore the genetic etiology for a Chinese pedigree affected with Alazami syndrome. METHODS: Genomic DNA was extracted for 2 patients and 2 unaffected members from the pedigree. Whole exome sequencing was carried out to detect potential variant in the proband, and the result was verified by Sanger sequencing. RESULTS: The proband and her sister were both found to harbor compound heterozygous variants of LARP7 gene, namely c.94A>T (p.Lys32*) and c.1141A>G (p.Lys381Glu), which were inherited from their father and mother, respectively. Both variants were predicted to be pathogenic based on bioinformatic analysis. CONCLUSION: The two variants of the LARP7 gene, both were unreported previously, probably underlay the Alazami syndrome in this pedigree. Above finding has expanded the mutational spectrum of the LARP7 gene.

The Optimal Design of Bifactor Multidimensional Computerized Adaptive Testing with Mixed-format Items.

Multidimensional computerized adaptive testing (MCAT) using mixed-format items holds great potential for the next-generation assessments. Two critical factors in the mixed-format test design (i.e., the order and proportion of polytomous items) and item selection were addressed in the context of mixed-format bifactor MCAT. For item selection, this article presents the derivation of the Fisher information matrix of the bifactor graded response model and the application of the bifactor dimension reduction method to simplify the computation of the mutual information (MI) item selection method. In a simulation study, different MCAT designs were compared with varying proportions of polytomous items (0.2-0.6, 1), different item-delivering formats (DPmix: delivering polytomous items at the final stage; RPmix: random delivering), three bifactor patterns (low, middle, and high), and two item selection methods (Bayesian D-optimality and MI). Simulation results suggested that a) the overall estimation precision increased with a higher bifactor pattern; b) the two item selection methods did not show substantial differences in estimation precision; and c) the RPmix format always led to more precise interim and final estimates than the DPmix format. The proportions of 0.3 and 0.4 were recommended for the RPmix and DPmix formats, respectively.

Application of Dimension Reduction to CAT Item Selection Under the Bifactor Model.

Multidimensional computerized adaptive testing (MCAT) based on the bifactor model is suitable for tests with multidimensional bifactor measurement structures. Several item selection methods that proved to be more advantageous than the maximum Fisher information method are not practical for bifactor MCAT due to time-consuming computations resulting from high dimensionality. To make them applicable in bifactor MCAT, dimension reduction is applied to four item selection methods, which are the posterior-weighted Fisher D-optimality (PDO) and three non-Fisher information-based methods-posterior expected Kullback-Leibler information (PKL), continuous entropy (CE), and mutual information (MI). They were compared with the Bayesian D-optimality (BDO) method in terms of estimation precision. When both the general and group factors are the measurement objectives, BDO, PDO, CE, and MI perform equally well and better than PKL. When the group factors represent nuisance dimensions, MI and CE perform the best in estimating the general factor, followed by the BDO, PDO, and PKL. How the bifactor pattern and test length affect estimation accuracy was also discussed.

[Determination of IgG content of IVIG by improved rocket immune electrophoresis].

OBJECTIVE: To establish a specific method for determination of IgG in IVIG. METHODS: The IVIG samples were disposed by acylation and analyzed by Rocket Immunoelectrophoresis. The amount of the IgG in IVIG was calculated by an IgG standard curve. RESULTS: The standard curve by this method has a very good linear relationship: r = 0.9967. The reproducibilities with 3 bathes of IVIG samples (n = 6) are 5.37% +/- 0.21%, 5.28% +/- 0.39% and 5.80% +/- 0.30%. CONCLUSION: This method could be adapted to regular assay in blood products.