Genetic mapping of three human homologues of murine t-complex genes localizes TCP10 to 6q27, 15 cM distal to TCP1 and PLG

Human homologues of mouse t-complex genes have been cloned and localized physically to chromosome 6p or 6q. TCP1, TCP10, and PLG are human homologues of genes located in the proximal portion of the t-complex on mouse chromosome 17. We present here results of genetic mapping of these human t-complex homologues previously localized to 6q25-q27, 6q21-q27, and 6q26-q27, respectively, by physical techniques. TCP1 and PLG do not recombine with each other and are separated from TCP10 by about 15 cM, while the corresponding mouse genes are no more than 4 cM apart. Genetic mapping with markers well localized cytogenetically places TCP1 and PLG proximal to TCP10 and localizes the latter to the cytogenetic band 6q27. It is likely that the organization of human t-complex homologues on 6q is similar to that of t haplotypes rather than that of wildtype murine chromosome 17.     

Phylogenetic relationships of Blepharisma americanum and Colpoda inflata within the phylum ciliophora inferred from complete small subunit rRNA gene sequences

The complete small subunit rRNA gene sequences of the heterotrich Blepharisma americanum and the colpodid Colpoda inflata were determined to be 1719 and 1786 nucleotides respectively. The phylogeny produced by comparisons with other ciliates indicated that C. inflata is allied more closely with the nassophoreans and oligohymenophoreans than the spirotrichs. This is consistent with the placement of the colpodids in the Class Copodea. Blepharisma americanum was not grouped with the hypotrichs but instead was placed as the earliest branching ciliate. The distinct separation of B. americanum supports the elevation to class status given the heterotrichs based on morphological characters.     

Expression of the Opc protein correlates with invasion of epithelial and endothelial cells by Neisseria meningitidis

Whereas capsulate strains of Neisseria meningitidis are dependent on pili for adhesion to human endothelial and epithelial cells, strains which lacked assembled pili and were partially capsule-deficient adhered to and invaded human endothelial and epithelial cells if they expressed the Opc protein. Bacteria expressing low or undetectable levels of Opc protein failed to adhere to or invade eukaryotic cells. In addition, the presence of OpaAC751 protein on the surface of bacteria did not increase bacterial interactions with host cells. Association of Opc-expressing bacteria was inhibited by antibodies against Opc. Invasion was dependent on the host-cell cytoskeletal activity and was inhibited by cytochalasin D. In some cells, infected at the apical surface, bacteria emerging from basal surface were detected by electron microscopy. Opc is found in diverse meningococci and may represent a common virulence factor which facilitates adherence and invasion by these bacteria.     

Segmental release of amino acid neurotransmitters from transcranial stimulation

The present study used microdialysis techniques in an intact rabbit model to measure the release of amino acids within the lumbar spinal cord in response to transcranial electrical stimulation. Dialysis samples from the extracellular space were obtained over a stimulation period of 90 minutes and were examined using high pressure liquid chromatography. Neuronal excitation was verified by recerding corticomotor evoked potentials (CMEPs) from the spinal cord. A significant increase in the release of glycine and taurine compared to sham animals was measured after 90 minutes of transcranial stimulation. Glutamate and aspartate release was not significantly elevated. GABA concentrations were consistently low. CMEP components repeatedly showed adequate activation of descending fiber pathways and segmental interneuron pools during dialysis sampling. Since glycine, and to a lesser extent taurine, have been shown to inhibit motor neuron activity and are closely associated with segmental interneuron pools, suprasegmental modulation of motor activity may be, in part, through these inhibitory amino acid neurotransmitters in the rabbit lumbar spinal cord.     

Margaret Mead and Samoa: Coming of Age in Fact and Fiction

Derek Freeman's 1983 critique of Margaret Mead's Coming of Age in Samoa has prompted one of the most heated debates in recent anthropological memory. Yet even Mead's defenders have generally accepted the view that she saw Samoa as a romantic paradise. Here I argue that a careful reading of Coming of Age shows quite a different picture. In my reanalysis, Mead's work emerges as complex and somewhat enigmatic, with facile conclusions standing in contrast to much rich and sensitive ethnography. My goal in this article is to highlight what Mead actually said, pointing up the notable discrepancy between the popular perception and her actual account.