Early nasal continuous positive airway pressure in a cohort of the smallest infants in Denmark: neurodevelopmental outcome at five years of age

AIM: To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period. METHODS: A national prospective observational study was conducted in Denmark which included all 269 surviving children with a birthweight below 1000 g or a gestational age below 28 wk born in Denmark in between 1994 and 1995. A total of 164 children (61%) had been treated with nasal CPAP only in the neonatal period. A reference group (n = 76) of term children was studied in parallel. RESULTS: Of the 269 surviving children, 252 (94%) were examined. Twenty-four children (10%) had cerebral palsy, and three children were blind. No case of hearing impairment was detected. Nineteen percent of the index children had an IQ score <-- 2 SD and 42% had an IQ score <-- 1 SD of the mean score of the reference group. CONCLUSIONS: The intellectual development of children in this cohort treated with early nasal CPAP did not suggest a higher proportion of adverse effects on the brain compared to the published follow-up studies of preterm children treated with mechanical ventilation. In our population-based cohort, however, the survival rate for infants below 25 wk of gestation was relatively low and this may indicate a limit for the use of early nasal CPAP.     

Reference Values for Valve Circumferences and Ventricular Wall Thicknesses of Fetal and Neonatal Hearts

To evaluate valvular stenosis, cardiac dilation, and/or cardiac hypertrophy, measurements of valve circumference and ventricular wall thickness are of importance. To establish reference values in fetuses and neonates, we reviewed pathology reports at Women and Infants Hospital from 1978 through 2002 and found measurements in 776 cases that were suitable for analysis. Gestational ages (GA) ranged from 15 to 42 wk. The tabulated data include the mean, standard deviation, and 10th and 90th percentile values for foot length, body weight, body length, heart weight, valve measurements, and ventricular wall thicknesses for each week of GA. In cases in which clinical dating is not reliable, we estimated the GA by the mean value nearest that of the observed foot length. All linear measurements increased in a linear fashion throughout the second and third trimesters of development. The circumferences of cardiac valves at all ages, in descending order of magnitude, are: tricuspid, mitral, pulmonary, and aortic. Mean left ventricular (LV) wall thickness is greater than mean right ventricular (RV) wall thickness throughout gestation. The tables offer a means of determining valvular stenosis, or cardiac dilation and/or hypertrophy, based on various gestational ages.     

The risk of birth defects in children born after assisted reproductive technologies

PURPOSE OF REVIEW: This review addresses the question of whether there is evidence of an increased risk of birth defects in children born following assisted reproductive technologies compared with spontaneously conceived children. RECENT FINDINGS: Three recent studies added relatively little new information given their modest size (56-472 assisted reproductive technology children). We therefore considered all published papers that compared birth defects in children born following assisted reproductive technologies with those in children born following spontaneous conception. Overall, only six of the 26 relevant papers concluded there was an increased risk of birth defects following assisted reproductive technologies. The interpretation of many studies was based on statistical significance testing alone. When results showed a greater proportion of defects in the assisted reproductive technology group compared with the spontaneous group, but the results were not statistically significant, this was often interpreted as showing no increase in risk, rather than an increase in risk that may have been due to chance. The vast majority of individual studies were too small to have sufficient power to detect, as statistically significant, clinically relevant results. We found that although only eight (30%) of the studies had statistically significant results, 24 (89%) had an odds ratio estimate comparing assisted reproductive technology with spontaneously conceived children of over 1.0; 19 (70%) had an estimate of 1.20 or greater; and 14 (52%) had an estimate of 1.5 or greater. SUMMARY: Current evidence suggests there is an elevated risk of birth defects in children born following assisted reproductive technologies. Whilst others may disagree with our interpretation, one certainly cannot exclude this possibility on the basis of the current evidence.     

Optimizing the fMRI data-processing pipeline using prediction and reproducibility performance metrics: I. A preliminary group analysis

We argue that published results demonstrate that new insights into human brain function may be obscured by poor and/or limited choices in the data-processing pipeline, and review the work on performance metrics for optimizing pipelines: prediction, reproducibility, and related empirical Receiver Operating Characteristic (ROC) curve metrics. Using the NPAIRS split-half resampling framework for estimating prediction/reproducibility metrics (Strother et al., 2002), we illustrate its use by testing the relative importance of selected pipeline components (interpolation, in-plane spatial smoothing, temporal detrending, and between-subject alignment) in a group analysis of BOLD-fMRI scans from 16 subjects performing a block-design, parametric-static-force task. Large-scale brain networks were detected using a multivariate linear discriminant analysis (canonical variates analysis, CVA) that was tuned to fit the data. We found that tuning the CVA model and spatial smoothing were the most important processing parameters. Temporal detrending was essential to remove low-frequency, reproducing time trends; the number of cosine basis functions for detrending was optimized by assuming that separate epochs of baseline scans have constant, equal means, and this assumption was assessed with prediction metrics. Higher-order polynomial warps compared to affine alignment had only a minor impact on the performance metrics. We found that both prediction and reproducibility metrics were required for optimizing the pipeline and give somewhat different results. Moreover, the parameter settings of components in the pipeline interact so that the current practice of reporting the optimization of components tested in relative isolation is unlikely to lead to fully optimized processing pipelines.     

Outcomes of antireflux surgery in patients with normal preoperative 24-hour pH test results

OBJECTIVE: Preoperative 24-hour pH testing is controversial in surgical patients who have symptomatic gastroesophageal reflux disease (GERD) and endoscopic evidence of esophagitis. The objective of this study was to compare the clinical outcomes of Nissen fundoplication for symptomatic reflux between patients with normal and abnormal preoperative pH testing. METHODS: Patients were selected from a prospective database of patients who underwent laparoscopic esophageal procedures between January 1997 and December 2001 at our institution. Only patients having typical symptoms of GERD (heartburn and/or reflux), preoperative pH testing, manometry, and endoscopy and who had at least 6 months of post-operative follow-up were included in the study. Fifteen patients had normal preoperative DeMeester scores (DMS) (median 11.4, range 3.3 to 14.7). These were compared with 208 consecutive patients having abnormal preoperative DMS (median 49.6, range 15.2 to 250). Logistic regression modeling was performed to identify variables significant for poor outcome. Differences between means were tested using appropriate parametric or nonparametric tests. RESULTS: There were no statistically significant differences in demographics, preoperative symptom score (mean 2.9 +/- 1.1 vs. 3.1 +/- 0.68, P = 0.30), or preoperative grade of esophagitis (P = 0.37) between the 2 groups. After a median follow-up of 8.8 months (range 6 to 36), 6 (40%) of the patients having normal preoperative DMS and 17 (8.1%) of the patients having abnormal preoperative DMS continued to have typical GERD symptoms (P <0.01, B error = 0.02). The most significant factor for poor outcome in the regression model was normal preoperative pH (odds ratio 9.02, P <0.01). CONCLUSIONS: Symptomatic GERD patients with normal preoperative 24-hour pH test results have significantly worse subjective outcomes after Nissen fundoplication compared with patients having abnormal preoperative pH test results. To minimize poor symptomatic outcomes after antireflux surgery, a policy of routine preoperative pH testing is advised.     

Wall shear rates differ between the normal carotid, femoral, and brachial arteries: an in vivo MRI study

PURPOSE: To investigate wall shear rates in vivo in the common carotid, brachial, and superficial femoral arteries using very high resolution magnetic resonance imaging (MRI) phase contrast measurements. MATERIALS AND METHODS: Mean, maximum, and minimum wall shear rate and an oscillatory shear index were measured for 20 volunteers, aged 23.3 +/- 1.9 years, in the three arteries, using phase contrast imaging with 0.0625 mm2 resolution and three-dimensional paraboloid fitting. RESULTS: The superficial femoral artery had the lowest mean (130.3 +/- 13.1 second(-1)), maximum (735.8 +/- 32.4 second(-1)), and minimum (-224.5 +/- 17.0 second(-1)) wall shear rate, as well as the highest oscillatory shear index (0.21 +/- 0.02). All values were significantly different (P < 0.05) from both the brachial artery and the common carotid artery values. The highest mean (333.3 +/- 13.6 second(-1)) and minimum (117.9 +/- 24.5 second(-1)) wall shear rates and the lowest oscillatory shear index (0 +/- 0) were found in the common carotid artery. CONCLUSION: It is possible to measure wall shear rate in vivo in different arteries using MRI with very high resolution. The findings exhibit the in vivo environment of wall shear rates and suggest a nonuniform distribution of wall shear rates throughout the arterial system.