Age, sex, and performance influence the visuospatial working memory network in childhood

This study describes the influence of age, sex, and working memory (WM) performance on the visuospatial WM network. Thirty-nine healthy children (7-12 years) completed a dot location functional magnetic resonance imaging (fMRI) task. Percent signal change measured the intensity and laterality indices measured the asymmetry of activation in frontal and parietal brain regions. Old children showed greater intensity of activation in parietal regions than young children but no differences in lateralization were observed. Intensity of activation was similar across sex and WM performance groups. Girls and high WM performers showed more right-sided lateralization of parietal regions than boys and low WM performers.

Chronic pulmonary valve insufficiency after repaired tetralogy of Fallot: diagnostics, reoperations and reconstruction possibilities

Complete correction of Tetralogy of Fallot, the most common cyanotic congenital heart defect, has now become routine. However, late residual lesions, primarily chronic pulmonary valve insufficiency, may have a negative impact on right-ventricular function, leading to the need for reoperation to insert a competent valve at the right-ventricular outflow. The diagnostic modalities pertaining to the failing right ventricle, the timing for eventual reintervention and the various surgical reconstruction possibilities of the right-ventricular outflow tract are still controversial and evolving, and are reviewed with a brief overview on current trends and future outlooks.

Global phylogenomic analysis of nonencapsulated Streptococcus pneumoniae reveals a deep-branching classic lineage that is distinct from multiple sporadic lineages.

The surrounding capsule of Streptococcus pneumoniae has been identified as a major virulence factor and is targeted by pneumococcal conjugate vaccines (PCV). However, nonencapsulated Streptococcus pneumoniae (Non-Ec-Sp) have also been isolated globally, mainly in carriage studies. It is unknown if Non-Ec-Sp evolve sporadically, if they have high antibiotic non-susceptiblity rates and a unique, specific gene content. Here, whole genome sequencing of 131 Non-Ec-Sp isolates sourced from 17 different locations around the world was performed. Results revealed a deep-branching classic lineage that is distinct from multiple sporadic lineages. The sporadic lineages clustered with a previously sequenced, global collection of encapsulated S. pneumoniae (Ec-Sp) isolates while the classic lineage is comprised mainly of the frequently identified multi-locus sequences types ST344 (n=39) and ST448 (n=40). All ST344 and nine ST448 isolates had high non-susceptiblity rates to β-lactams and other antimicrobials. Analysis of the accessory genome reveals that the classic Non-Ec-Sp contained an increased number of mobile elements, than Ec-Sp and sporadic Non-Ec-Sp. Performing adherence assays to human epithelial cells for selected classic and sporadic Non-Ec-Sp revealed that the presence of a integrative conjugative element (ICE) results in increased adherence to human epithelial cells (P=0.005). In contrast, sporadic Non-Ec-Sp lacking the ICE had greater growth in vitro possibly resulting in improved fitness. In conclusion, Non-Ec-Sp isolates from the classic lineage have evolved separately. They have spread globally, are well adapted to nasopharyngeal carriage and are able to coexist with Ec-Sp. Due to continued use of pneumococcal conjugate vaccines, Non-Ec-Sp may become more prevalent.

Dog bites man or man bites dog? The enigma of the amino acid conjugations

The proposition posed is that the value of amino acid conjugation to the organism is not, as in the traditional view, to use amino acids for the detoxication of aromatic acids. Rather, the converse is more likely, to use aromatic acids that originate from the diet and gut microbiota to assist in the regulation of body stores of amino acids, such as glycine, glutamate, and, in certain invertebrates, arginine, that are key neurotransmitters in the central nervous system (CNS). As such, the amino acid conjugations are not so much detoxication reactions, rather they are homeostatic and neuroregulatory processes. Experimental data have been culled in support of this hypothesis from a broad range of scientific and clinical literature. Such data include the low detoxication value of amino acid conjugations and the Janus nature of certain amino acids that are both neurotransmitters and apparent conjugating agents. Amino acid scavenging mechanisms in blood deplete brain amino acids. Amino acids glutamate and glycine when trafficked from brain are metabolized to conjugates of aromatic acids in hepatic mitochondria and then irreversibly excreted into urine. This process is used clinically to deplete excess nitrogen in cases of urea cycle enzymopathies through excretion of glycine or glutamine as their aromatic acid conjugates. Untoward effects of high-dose phenylacetic acid surround CNS toxicity. There appears to be a relationship between extent of glycine scavenging by benzoic acid and psychomotor function. Glycine and glutamine scavenging by conjugation with aromatic acids may have important psychosomatic consequences that link diet to health, wellbeing, and disease.

Excellent outcome after surgical treatment of massive pulmonary embolism in critically ill patients

OBJECTIVE: Treatment of central and paracentral pulmonary embolism in patients with hemodynamic compromise remains a subject of debate, and no consensus exists regarding the best method: thrombolytic agents, catheter-based thrombus aspiration or fragmentation, or surgical embolectomy. We reviewed our experience with emergency surgical pulmonary embolectomy. METHODS: Between January of 2000 and March of 2007, 25 patients (17 male, mean age 60 years) underwent emergency open embolectomy for central and paracentral pulmonary embolism. Eighteen patients presented in cardiogenic shock, 8 of whom had cardiac arrest and required cardiopulmonary resuscitation. All patients underwent operation with mild hypothermic cardiopulmonary bypass. Concomitant procedures were performed in 8 patients (3 coronary artery bypass grafts, 2 patent foramen ovale closures, 4 ligations of the left atrial appendage, 3 removals of a right atrial thrombus). Follow-up is 96% complete with a median of 2 years (range, 2 months to 6 years). RESULTS: All patients survived the procedure, but 2 patients died in the hospital on postoperative days 1 (intracerebral bleeding) and 11 (multiorgan failure), accounting for a 30-day mortality of 8% (95% confidence interval: 0.98-0.26). Four patients died later because of their underlying disease. Pre- and postoperative echocardiographic pressure measurements demonstrated the reduction of the pulmonary hypertension to half of the systemic pressure values or less. CONCLUSION: Surgical pulmonary embolectomy is an excellent option for patients with major pulmonary embolism and can be performed with minimal mortality and morbidity. Even patients who present with cardiac arrest and require preoperative cardiopulmonary resuscitation show satisfying results. Immediate surgical desobstruction favorably influences the pulmonary pressure and the recovery of right ventricular function, and remains the treatment of choice for patients with massive central and paracentral embolism with hemodynamic and respiratory compromise.