Clinical significance of isolated mega cisterna magna

Objective The prevalence and clinical significance of isolated mega cisterna magna in both fetuses and adults is not yet well defined. It is therefore difficult to provide reliable parental counseling in cases of a fetal sonographic diagnosis of this anomaly. The aim of the present study was to, determine the cognitive profile of adults with isolated mega cisterna magna. Methods We reviewed 19,301 consecutive CT/MRI of the brain. Isolated mega cisterna magna was observed in 49 cases. A battery of neuropsychological tests was performed in 18 adults with this anomaly and in 18 controls who had no brain anomaly on CT/MRI. Results Subjects with isolated mega cisterna magna had a lower performance on memory tasks [RAVLT saving score (0.8 ± 0.2 vs. 1.02 ± 0.2, P = 0.003)] and verbal fluency [phonemic fluency (9.4 ± 4.5 vs. 13.6 ± 5.3, P = 0.02), semantic fluency (19.8 ± 5.8 vs. 24.4 ± 7.5, P = 0.05)]. They did not differ from controls in regard to the Raven similarity tests indicating that this brain anomaly is not associated with impairment of general cognitive abilities. Conclusion Adults with isolated mega cisterna have an overall normal cognitive functioning but may score inferior to controls on some parameters of memory and verbal fluency. Although application of adult cases to the fetuses is not well established, this information might be of value in parental counseling in cases of a fetus with this anomaly.     

Reduction of nasopharyngeal carriage of Streptococcus pneumoniae after administration of a 9-valent pneumococcal conjugate vaccine to toddlers attending day care centers

A double-blind, randomized study involving 264 toddlers attending day care centers was conducted to document the effect of a 9-valent pneumococcal conjugate vaccine on the carriage rate of pneumococci. Of 3750 cultures done on nasopharyngeal samples obtained from subjects during a 2-year follow-up period after vaccination, 65% were positive for Streptococcus pneumoniae. In all age windows, the rate of carriage of vaccine-type pneumococci was lower among subjects who received the pneumococcal vaccine than among control subjects, because the acquisition rate was lower in the former group. The effect was most pronounced among subjects aged < or =36 months. The sample size enabled us to study protection against carriage of S. pneumoniae serotypes 6B, 9V, 14, 19F, and 23F; significant protection against all serotypes except 19F was seen in the pneumococcal-vaccine group. The rate of carriage of serotype 6A (not included in the vaccine) was also reduced significantly, but the rate of carriage of serotype 19A (not included in the vaccine) was not. The rate of carriage of non-vaccine-type pneumococci (excluding serotype 6A) was higher in the pneumococcal-vaccine group than in the control group.     

High-resolution electrophysiological assessment of human embryonic stem cell-derived cardiomyocytes: a novel in vitro model for the study of conduction

The goal of the present report was to establish a new in vitro model for the study of impulse propagation in human cardiac tissue. By using the human embryonic stem cell differentiating system, spontaneously contracting areas were generated in three-dimensional differentiating cell aggregates (embryoid bodies). Morphological analysis revealed an isotropic tissue of early-stage cardiac phenotype. Gap junctions, assessed by immunostaining of connexin43 and connexin45, were distributed along the cell borders. High-resolution activation maps demonstrated the presence of a functional syncytium with stable focal activation and conduction properties. Conduction was significantly slower in narrow bands of contracting tissue compared with broad cardiomyocyte regions. Establishment of this unique in vitro human model may be used for the assessment of long-term structure-function relationships, for pharmacological studies, for tissue engineering, and may permit the study of genetically modified cardiomyocytes.