Anti-apoptotic peptides protect against radiation-induced cell death

The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15Gy radiation. In mice exposed to 5Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues.     

TAM receptor ligands in lupus: Protein S but not Gas6 levels reflect disease activity in systemic lupus erythematosus

Introduction  

The TAM (tyro 3, axl, mer) kinases are key regulators of innate immunity and are important in the phagocytosis of apoptotic cells. Gas6 and protein S are ligands for these TAM kinases and bind to phosphatidyl serine residues exposed during apoptosis. In animal models, absence of TAM kinases is associated with lupus-like disease. To test whether human systemic lupus erythematosus (SLE) patients might have deficient levels of TAM ligands, we measured Gas 6 and protein S levels in SLE.     

Ultrastructure of human labial salivary glands. 3. Myoepithelium and ducts

Myoepithelial cells were present between the basal lamina and the acinar secretory cells of human labial salivary glands. In form and disposition, they resembled myoepithelial cells in the major salivary glands. Many of these cells possessed single cilia on their upper surfaces. Such cilia occasionally extended into invaginations of the overlying secretory cell. The intercalated ducts were variable in occurrence. Their epithelium ranged from columnar to squamous, and showed few signs of secretory activity. Few intralobular ducts possessed basal striations. While mitochondria were abundant in non-striated cells, they were randomly disposed in both basal and apical cytoplasm, and the basal plasmalemma showed only occasional infoldings. The paucity of true striated ducts in labial salivary glands may be responsible for the high concentration of sodium and chloride in unstimulated labial gland salivary secretions.     

Metamorphic changes in the intestine of three species of lampreys

Measurements have been made of those changes which lead to increases in the surface area of the intestine during the metamorphosis of three species of lampreys. Although the intestine of the Southern Hemisphere lamprey, Geotria australis, increases in length by 1.13 times and in diameter by 1.12 times, the main factor influencing the 5.71 times increase in surface area is the development of longitudinal folds. The contribution of the typhlosole to the internal perimeter of the intestine is less in most life cycle stages of G. australis than in Lampetra spp. The changes in the various intestinal measurements of the nonparasitic species L. planeri parallel those of the presumed ancestral parasitic species, L. fluviatilis, during the first six stages of metamorphosis. However, the longitudinal folds, but not the typhlosole, subsequently start regressing in L. planeri just after the time when the rate of gonadal development increases markedly. An account is also given of the pattern of fold formation and the development of the typhlosolar vein in G. australis.