Spinal cord compression by spontaneous spinal subdural haematoma in polycythemia vera.

A woman with an eight-year history of polycythemia vera presented with numbness and weakness of both legs. A large spinal haematoma was revealed on magnetic resonance imaging which was treated clinically and which subsequently resolved.     

Computerized tomography fails to show calcification in diffuse retinoblastoma

A suspected diagnosis of retinoblastoma can almost always be supported by intraocular calcification detected by computerized tomography. We report two patients with diffuse unilateral opacification of the ocular media who failed to demonstrate calcification on a CT scan.     

Surfactant protein D enhances phagocytosis and killing of unencapsulated phase variants of Klebsiella pneumoniae

Pulmonary surfactant protein D (SP-D) is a collagenous C-type lectin (collectin) that is secreted into the alveoli and distal airways of the lung. We have studied the interactions of SP-D and alveolar macrophages with Klebsiella pneumoniae, a common cause of nosocomial pneumonia. SP-D does not agglutinate encapsulated K. pneumoniae but selectively agglutinates spontaneous, unencapsulated phase variants, such as Klebsiella strain K50-3OF, through interactions with their lipopolysaccharides (LPS). These effects are calcium dependent and inhibited with maltose but not lactose, consistent with involvement of the SP-D carbohydrate recognition domain. Precoating of K50-3OF with SP-D enhances the phagocytosis and killing of these organisms by rat alveolar macrophages in cell culture and stimulates the production of nitric oxide by the NR-8383 rat alveolar macrophage cell line. SP-D similarly enhances the NO response to K50-3OF LPS adsorbed to Latex beads under conditions where soluble LPS or SP-D, or soluble complexes of SP-D and LPS, do not stimulate NO production. Our studies demonstrate that interactions of SP-D with exposed arrays of Klebsiella LPS on a particulate surface can enhance the host defense activities of alveolar macrophages and suggest that activation of macrophages by SP-D requires binding to microorganisms or other particulate ligands. Because unencapsulated phase variants are likely to be responsible for the initial stages of tissue invasion and infection, we speculate that SP-D-mediated agglutination and/or opsonization of K. pneumoniae is an important defense mechanism for this respiratory pathogen in otherwise healthy individuals.     

Evaluating self-generated information: anterior prefrontal contributions to human cognition

The anterior or rostrolateral prefrontal cortex (RLPFC) is frequently recruited during complex cognitive tasks across a wide range of domains, including reasoning, long-term memory retrieval, and working memory. The authors report an event-related functional MRI study, indicating that the RLPFC is specifically involved in the evaluation of internally generated information--or information that cannot be readily perceived from the external environment but has to be inferred or self-generated. The findings are consistent with a hierarchical model of lateral prefrontal organization, with RLPFC contributing only at the highest orders of cognitive transformations. This characterization of RLPFC function may help explain seemingly disparate findings across multiple cognitive domains and could provide a unified account of this region's contribution to human cognition.     

Religious and Spiritual Development from Adolescence to Early Adulthood in the U.S.: Changes over Time and Sexual Orientation Differences

Archives of Sexual Behavior - Adolescence is a critical time in the U.S. for religious development in that many young people eschew their religious identity as they enter adulthood. In general,...