Hypothalamic Hamartomas: Evolving Understanding and Management

Hypothalamic hamartomas (HH) are rare, basilar developmental lesions with widespread comorbidities often associated with refractory epilepsy and encephalopathy. Imaging advances allow for early, even prenatal, detection. Genetic studies suggest mutations in GLI3 and other patterning genes are involved in HH pathogenesis. About 50-80% of children with HH suffer from severe rage and aggression and a majority of cases exhibit externalizing disorders. Behavioral disruption and intellectual disability may predate epilepsy. Neuropsychological, sleep and endocrine disorders are typical. The purpose of this paper is to provide a summary of the current understanding of HH, and to highlight opportunities for future research

Host Genetics and HIV-1: The Final Phase?

This is a crucial transition time for human genetics in general, and for HIV host genetics in particular. After years of equivocal results from candidate gene analyses, several genome-wide association studies have been published that looked at plasma viral load or disease progression. Results from other studies that used various large-scale approaches (siRNA screens, transcriptome or proteome analysis, comparative genomics) have also shed new light on retroviral pathogenesis. However, most of the inter-individual variability in response to HIV-1 infection remains to be explained: genome resequencing and systems biology approaches are now required to progress toward a better understanding of the complex interactions between HIV-1 and its human host

Toll-like receptor 4 signaling in liver injury and hepatic fibrogenesis

Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors (PRR) that play a key role in innate and adaptive immunity by recognizing structural components unique to bacteria, fungi and viruses. TLR4 is the most studied of the TLRs, and its primary exogenous ligand is lipopolysaccharide, a component of Gram-negative bacterial walls. In the absence of exogenous microbes, endogenous ligands including damage-associated molecular pattern molecules from damaged matrix and injured cells can also activate TLR4 signaling. In humans, single nucleotide polymorphisms of the TLR4 gene have an effect on its signal transduction and on associated risks of specific diseases, including cirrhosis. In liver, TLR4 is expressed by all parenchymal and non-parenchymal cell types, and contributes to tissue damage caused by a variety of etiologies. Intact TLR4 signaling was identified in hepatic stellate cells (HSCs), the major fibrogenic cell type in injured liver, and mediates key responses including an inflammatory phenotype, fibrogenesis and anti-apoptotic properties. Further clarification of the function and endogenous ligands of TLR4 signaling in HSCs and other liver cells could uncover novel mechanisms of fibrogenesis and facilitate the development of therapeutic strategies

HUMAN-IMMUNODEFICIENCY-VIRUS (HIV) TYPE-1 INFECTION STATUS AND IN-VITRO SUSCEPTIBILITY TO HIV-INFECTION AMONG HIGH-RISK HIV-1 SERONEGATIVE HEMOPHILIACS

Blood samples were obtained from 16 hemophiliacs who had a 50%-94% defined risk of human immunodeficiency virus (HIV type 1 infection on the basis of treatment history and from 14 controls not at risk for HIV infection. HIV-1 was not detected in any of 12 patient samples by cocultivation nor in 14 patient samples by the polymerase chain reaction. Peripheral blood cells from 7 seronegative hemophiliacs at highest risk of seroconversion (94%) were less susceptible to HIV-1 infection in vitro than were cells from healthy controls (P <.025, one-tailed Wilcoxon rank sum test). In contrast, the susceptibility to HIV-1 infection of lymphocytes from 6 seronegative hemophiliacs at moderate risk (50%-56%) of seroconversion did not differ from that of cells from controls or from high-risk hemophiliacs. Therefore, prolonged periods of seronegative HIV-1 infection are not common in this high-risk population. In addition, among hemophiliacs there may exist heterogeneity in susceptibility to HIV-1 infection in vitro and in vivo