Impact of sampling rate on statistical significance for single subject fMRI connectivity analysis

A typical time series in functional magnetic resonance imaging (fMRI) exhibits autocorrelation, that is, the samples of the time series are dependent. In addition, temporal filtering, one of the crucial steps in preprocessing of functional magnetic resonance images, induces its own autocorrelation. While performing connectivity analysis in fMRI, the impact of the autocorrelation is largely ignored. Recently, autocorrelation has been addressed by variance correction approaches, which are sensitive to the sampling rate. In this article, we aim to investigate the impact of the sampling rate on the variance correction approaches. Toward this end, we first derived a generalized expression for the variance of the sample Pearson correlation coefficient (SPCC) in terms of the sampling rate and the filter cutoff frequency, in addition to the autocorrelation and cross‐covariance functions of the time series. Through simulations, we illustrated the importance of the variance correction for a fixed sampling rate. Using the real resting state fMRI data sets, we demonstrated that the data sets with higher sampling rates were more prone to false positives, in agreement with the existing empirical reports. We further demonstrated with single subject results that for the data sets with higher sampling rates, the variance correction strategy restored the integrity of true connectivity.     

A retrospective analysis of the stability and relapse of soft and hard tissue change after bilateral sagittal split osteotomy for mandibular setback of 64 Taiwanese patients.

PURPOSE: This study was an analysis of the soft and hard tissue changes of the facial profile after bilateral sagittal splitting osteotomy for mandibular setback of Taiwanese patients. PATIENTS AND METHODS: We collected pre- and postsurgical lateral cephalographs of 64 patients (28 males, 36 females) with skeletal Class III malocclusion who received combined orthodontic-surgical treatment with bilateral sagittal splitting osteotomy mandibular setback at Taipei Veterans General Hospital between 1994 and 2000. Nineteen cephalometric parameters of (14 linear, 4 angular, and the BS index) soft and hard tissues were measured at 1 week before treatment, and 2 months and 1 year after surgery, and analyzed by paired t test. RESULTS: Mean patient age was 20.0 +/- 1.6 years. The patients underwent an average of 7 mm mandibular setback at the osseous pogonion (Pog). Average setbacks at Pog and soft tissue pogonion (pog) were 5.54 mm and 4.85 mm, respectively, at 1 year after surgery. The setback ratio of Pog/pog was 1:0.88. The hard tissue relapse at Pog was 21% at 1 year after surgery. Improvement in prognathic profile was demonstrated by significant changes in the positions of Pog and pog, ANB angle, the distance from lower lip to esthetic line (E-L lip), and the BS index after surgery. However, compared with parameters obtained from a normal Taiwanese population, the cephalometric data of Pog, pog, and BS index still indicated mild prognathism. CONCLUSION: Although mandibular prognathism could be grossly improved by bilateral sagittal splitting osteotomy mandibular setback, a significant amount of relapse occurred within 1 year after surgery. The extent of the postoperatively preserved features showing mandibular prognathism should be a concern for both patients and physicians.     

Effect of a new synthetic serum replacement on insulin and somatostatin secretion from isolated rat pancreatic islets in long-term culture

Summary Serum contains insulin degrading components. We have evaluated the insulin and somatostatin secretion from isolated rat pancreatic islets during a 2-wk culture period using three different serum-containing media, and one serum-free medium with a synthetic serum replacement. Islets incubated in serum-free medium elicited significantly higher daily insulin and somatostatin secretions than islets incubated in the serum-containing media. After a 2-wk culture period, islets from the serum-free medium secreted significantly more insulin and somatostatin than islets cultured in other media when stimulated with 25 mmol/liter glucose together with 15 mmol/liter theophylline. We conclude that the serum-free medium is superior for long-term culture of rat pancreatic islets.     

Hypertrophic obstructive cardiomyopathy with infundibular stenosis treated by alcohol ablation therapy

This report describes an uncommon case of hypertrophic obstructive cardiomyopathy (HOCM) accompanying infundibular stenosis of the right ventricle treated by alcohol ablation therapy, in a 28-yr-old male patient presenting with dyspnea on exertion. HOCM with infundibular stenosis was detected by echocardiogram and cardiac catheterization and patient has dynamic obstructions of both ventricular outflow tracts. We performed alcohol ablation therapy to improve clinical symptoms and to relieve dynamic obstructions of both ventricular outflow tracts. This is the first case in which HOCM with infundibular stenosis of the right ventricle was treated by alcohol ablation therapy.     

Immunophenotypic analysis of the transformation zone of human cervix

The immunocompetent cell population of the cervical transformation zone of 18 uteri removed for noncervical disease, has been investigated with monoclonal antibodies. The panel included Leu 2a, 3a, 4, 14, and IL II receptor for lymphocytes and T cell subsets, Leu 7 for NK cells, Leu M5, Leu 10, HLA-DR, DRC 1 for dendritic cells, and Leu 6 for Langerhans' cells (LC). In ectocervical epithelium HLA-DR, Leu 6 and Leu 10 antibodies identified subpopulations of dendritic cells which differed in number and in topographic distribution. Furthermore, a strong HLA-DR epithelial positivity was constantly observed in endocervical columnar cells as well as in keratinocytes of squamous metaplasia. Leu 2a+ cells (T suppressor/cytotoxic) prevailed in the stromal and epithelial compartments of ecto/endocervix; in 6 cases, however, Leu 3a+ cells (T helper/inducer) represented the main T cell subset in the ectocervical stroma. B lymphocytes were occasionally noticed in the subepithelial stroma while NK and DRC-1 cells were never observed. Finally, only few lymphocytes displayed a positivity for IL II receptor. This study suggests that several phenotypes of intraepithelial dendritic cells are present in the transformation zone and that endocervical columnar cells and keratinocytes of squamous metaplasia express HLA-DR products; the latter finding may be related to the presence of intraepithelial and stromal T lymphocytes.     

Low Bone Mineral Density at Initial Diagnosis in Children and Adolescents with Graves’ Disease

Previous studies have reported reduced bone mineral density (BMD) in patients with hyperthyroidism. We assessed the association of BMD in children and adolescents with Graves’ disease (GD) after correcting for potential confounders affecting BMD such as age, sex, and pubertal status. Forty-four children and adolescents with GD and 172 age- and sex-matched healthy controls were enrolled in this study. We analyzed auxological features, BMD, and levels of thyroid hormone, thyroid-stimulating hormone, and thyroid autoantibodies. We measured BMD by dual-energy X-ray absorptiometry at the time of diagnosis in all patients. The mean age of all patients with GD (9 boys and 32 girls) was 12.1 ± 2.2 years (range, 7.0–16.0). Their initial mean free T4 and thyroid-stimulating hormone levels were 3.51 ± 1.56 ng/dL and 0.04 ± 0.03 IU/L, respectively. The mean BMD Z-scores of the lumbar spine (LS), femoral neck, and total body less head of patients with GD were significantly lower than those of control subjects. Eleven patients (26.8%) had low bone density (LS BMD Z-scores < ?2.0). To identify correlations of patient characteristics with BMD Z-scores at each site, alkaline phosphatase had a significant negative correlation with BMD Z-scores at LS and femoral neck, but not total body less head (r = ?0.441; p = 0.004 and r = ?0.351; p = 0.025, respectively). Children and adolescents with newly diagnosed GD had lower bone mass than their healthy peers. These results suggest that BMD measurement at initial evaluation may be necessary in this population.     

Exposure to Landfill Leachates Affects the Embryonic Development of Zebrafish,Danio rerio: A Case Study in Yucatan,Mexico

Bulletin of Environmental Contamination and Toxicology - We report the chemical characterisation and toxic effects of municipal solid waste landfill leachates on the embryonic development of Danio...     

A chronic toxicity study of diphenylarsinic acid in F344 rats in drinking water for 52 weeks

Diphenylarsinic acid (DPAA), a chemical warfare-related neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping after World War II. The purpose of the present study was to evaluate the potential toxicity of DPAA when administered to rats in their drinking water for 52 weeks. DPAA was administered to groups 1–4 at concentrations of 0, 5, 10, and 20 ppm in their drinking water for 52 weeks. There were no significant differences in the final body weights between the control groups and the treatment groups in male or female rats. In serum biochemistry, in females 20 ppm DPAA significantly increased alkaline phosphatase and γ-glitamyl transferase compared to controls, and 10 and 20 ppm DPAA significantly increased total cholesterol compared to controls. Absolute and relative liver weights were significantly increased in females treated with 20 ppm DPAA compared to the control group. Dilation of the common bile duct outside the papilla of Vater and stenosis of the papilla of Vater was observed in all male and female rats administered 20 ppm DPAA. The incidence of intrahepatic bile duct hyperplasia was significantly increased in male and female rats treated with 20 ppm DPAA compared to the control groups. These results suggest that DPAA is toxic to the bile duct epithelium in rats. The no-observed adverse effect levels of DPAA were estimated to be 10 ppm (0.48 mg/kg b.w./day) for males and 5 ppm (0.35 mg/kg b.w./day) for females under the conditions of this study.     

Body Fat Assessment Method Using CT Images with Separation Mask Algorithm

In recent years, the number of obese population in Korea has been growing up along with the economic development, environmental factors, and the change in life style. Considering the growth of obese population and the adverse effect of obesity on health, it is getting more important to prevent and diagnose the obesity with the quantitative measurement of body fat that has become an important indicator for obesity. In this study, we proposed a procedure for the automated fat assessment from computed tomography (CT) data using image processing technique. The proposed method was applied to a single-CT image as well as CT-volume data, and results were correlated to those of dual-energy X-ray absorptiometry (DEXA) that is known as the reliable method for evaluating body fat. Using single-CT images, correlation coefficients between DEXA and the automated assessment and DEXA and the manual assessment were 0.038 and 0.058, respectively (P > 0.05). Hence, there was no significant correlation between three methods using the proposed method with single-CT images. On the other hand, in case of CT-volume data, the above correlation coefficients were increased to 0.826, 0.812, and 0.805, respectively (P < 0.01). Thus, DEXA and the proposed methods with CT-volume data showed highly significant correlation with each other. The results suggest that the proposed automated assessment using CT-volume data is a reliable method for the evaluation of body fat. It is expected that the clinical application of the proposed procedure will be helpful to reduce the time for the quantitative evaluation of patient’s body fat.     

Epidemiologic Study on Kawasaki Disease in Korea, 2007-2014: Based on Health Insurance Review & Assessment Service Claims

The aim of this study is to assess the actual epidemiologic features of Kawasaki disease (KD) in Korea using the data from Health Insurance Review & Assessment Service (HIRA) claims from 2007 to 2014. We investigated HIRA claims of patients who had KD (International Classification of Diseases-10, M30.3) as a major diagnosis and were given intravenous immunoglobulin (IVIG) from 2007 to 2014. A total of 39,082 patients were reported during the period. The male-to-female ratio was 1.42 and the median age was 28 months. The incidence rates were 168.3 per 100,000 population aged 0 to 4 years in 2007, 159.1 in 2008, 167.3 in 2009, 190.4 in 2010, 188.2 in 2011, 190.2 in 2012, 210.4 in 2013 and 217.2 in 2014. These rates were much higher than those in the previous studies in Korea. KD occurred more often in early summer (May, June and July) and winter (December and January). The annual incidence rate of KD had been increasing every year, reaching 217.2 per 100,000 population aged 0 to 4 years in 2014. It is the second highest incidence rate of KD in the world after Japan.