Evidence implicating Gfi-1 and Pim-1 in pre-T-cell differentiation steps associated with beta-selection

After rearrangement of the T-cell receptor (TCR) beta-locus, early CD4(-)/CD8(-) double negative (DN) thymic T-cells undergo a process termed 'beta-selection' that allows the preferential expansion of cells with a functional TCR beta-chain. This process leads to the formation of a rapidly cycling subset of DN cells that subsequently develop into CD4(+)/CD8(+) double positive (DP) cells. Using transgenic mice that constitutively express the zinc finger protein Gfi-1 and the serine/threonine kinase Pim-1, we found that the levels of both proteins are important for the correct development of DP cells from DN precursors at the stage where 'beta-selection' occurs. Analysis of the CD25(+)/CD44(-,lo) DN subpopulation from these animals revealed that Gfi-1 inhibits and Pim-1 promotes the development of larger beta-selected cycling cells ('L subset') from smaller resting cells ('E subset') within this subpopulation. We conclude from our data that both proteins, Pim-1 and Gfi-1, participate in the regulation of beta-selection-associated pre-T-cell differentiation in opposite directions and that the ratio of both proteins is important for pre-T-cells to pass the 'E' to 'L' transition correctly during beta-selection.     

Lipid-protein interactions with native and modified myelin basic protein

The basic protein of central nervous system myelin has been shown to form complexes with acidic lipids in vitro. We measured the interaction of myelin basic protein with several charged and neutral lipids in a biphasic chloroform/methanol/water system and investigated the effect of decreasing the electrical charge of the basic amino groups of the myelin basic protein by acetylation. The modified myelin basic protein, which has an average of eight acetyl residues incorporated, was characterised by gel electrophoresis and circular dichroism. Complexes formed between the acetylated myelin basic protein and acidic lipids exhibited a reduction in the amount of lipids bound, a value that could be correlated with the number of modified amino groups. The significance of these experiments with reference to protein-lipid interaction in the myelin membrane is discussed.     

Binary display using pseudo-random ensembles with selected distributions

A binary display is produced from a continuous-tone image. An ensemble of pseudo-random numbers is added to the density sample values of the image and the result thresholded. If the ensemble is generated to have the appropriate cumulative probability distribution, the image is reproduced with a desired reproduction curve.     

Spigelian hernia

Spigelian hernia is very rare. Together with the direct inguinal hernia which emerges between the inferior epigastric artery and the edge of the rectus muscle, it is more frequent. Congenital openings in the aponeurosis of the transverse muscle permit the hernia either above or under the inferior epigastric artery. Due to neglect of this type of hernia and absence of herniation, the diagnosis can be difficult. Complaints are often uncharacteristic. Surgical intervention is indicated.     

Experimental demonstration of an identic antigenicity of the inner ear and kidney (author's transl)

An allergic glomerunephritis was produced in rats by injection of an anti-basement-membrane-serum (IgG-fraction), taken from rabbits which were sensitized against a basement membrane fraction of rat-glomerula. Tissues from heart, liver, brain, lung and inner ear were compared with the well known alterations of the glomerula. Exclusively in stria vascularis and renal glomerula heavy changements of the basement membranes and endothelial cells could be shown by electronmicroscopic examination and by immunohistological methods.     

A molecular orbital theoretical study on the acid-base property and reactivity of the charge relay system in alpha chymotrypsin

The disintegration of the nuclear envelope has been examined in nuclei and nuclear envelopes isolated from amphibian oocytes from amphibian oocytes and rat liver tissue, using different electron microscope techniques (ultrathin sections and negatively or positively stained spread preparations). Various treatments were studied, including disruption by surface tension forces, very low salt concentrations, and nonionic detergents such as Triton C-100 and Nonidet P-40. The highest local stability of the cylinders of nonmembranous pore complex material is emphasized. As progressive disintegration occurred in the membrane regions, a network of fibrils became apparent which interconnects the pore complexes and is distinguished from the pore complex-associated about 15-20 nm thick, located at the level of the inner nuclear membrane, which is recognized in thin sections to bridge the interpore distances. With all disintegraiton treatments a somewhat higher susceptibility of the outer nuclear membrane is notable, but a selective removal does not take place. Final stages of disintegration are generally characterized by the absence of identifiable, membrane-like structures. Analysis of detergent-treated nuclei and nuclear membrane fractions shows almost complete absence of lipid components but retention bo significant amount of glycoproteins with a typical endomembrane-type carbohydrate pattern. Various alternative interpretations of these observations are discussed. From the present observations and those of Aaronson and Blobel (1,2), we favor the notion that threadlike intrinsic membrane components are stabilized by their attachment to the pore complexes, and perhaps also to peripheral nuclear structures,and constitute a detergent-resistant, interpore skeleton meshwork.     

Externalizing symptoms among children of alcoholic parents: Entry points for an antisocial pathway to alcoholism.

The authors examined heterogeneity in risk for externalizing symptoms in children of alcoholic parents, as it may inform the search for entry points into an antisocial pathway to alcoholism. That is, they tested whether the number of alcoholic parents in a family, the comorbid subtype of parental alcoholism, and the gender of the child predicted trajectories of externalizing symptoms over the early life course, as assessed in high-risk samples of children of alcoholic parents and matched controls. Through integrative analyses of 2 independent, longitudinal studies, they showed that children with either an antisocial alcoholic parent or 2 alcoholic parents were at greatest risk for externalizing symptoms. Moreover, children with a depressed alcoholic parent did not differ from those with an antisocial alcoholic parent in reported symptoms. These findings were generally consistent across mother, father, and adolescent reports of symptoms; child gender and child age (ages 2 through 17); and the 2 independent studies examined. Multialcoholic and comorbid-alcoholic families may thus convey a genetic susceptibility to dysregulation along with environments that both exacerbate this susceptibility and provide few supports to offset it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)