Description of a new subgenus and a new species of Thamnocephalus (Crustacea: Branchiopoda,Anostraca) from the Salinas Grandes Basin,Córdoba Province,Argentina

At present, the American genus Thamnocephalus has three species, recorded from several states of U.S.A., México and Venezuela: Thamnocephalus platyurus Packard, T. mexicanus Linder and T. venezuelensis Belk & Pereira. The new species Thamnocephalus salinarum, from a turbid saline temporary pond inside the Salinas Grandes of Córdoba, Argentina is described here. The new species differs from all other congeners by the presence in the male, of an unbranched frontal appendage and a pair of soft cordiform parapenial lobes; also, by the sexually dimorphic caudal fin-like lobe. This new species may represent a new genus, however since only five specimens were collected it was not possible to observe if the penial ornamentation conforms to the Thamnocephalus type. Therefore, a conservative position is taken until new material allows proper analysis, by keeping the new species in the genus Thamnocephalus under the new subgenus Simplicephalus.     

Activation of NK cell-mediated cytotoxicity by a SAP-independent receptor of the CD2 family.

Some CD2 family receptors stimulate NK cell-mediated cytotoxicity through a signaling pathway, which is dependent on the recruitment of an adapter protein called SLAM-associated protein (SAP). In this work we identify a novel leukocyte cell surface receptor of the CD2 family called CD2-like receptor activating cytotoxic cells (CRACC). CRACC is expressed on cytotoxic lymphocytes, activated B cells, and mature dendritic cells, and activates NK cell-mediated cytotoxicity. Remarkably, although CRACC displays cytoplasmic motifs similar to those recruiting SAP, CRACC-mediated cytotoxicity occurs in the absence of SAP and requires activation of extracellular signal-regulated kinases-1/2. Thus, CRACC is a unique CD2-like receptor which mediates NK cell activation through a SAP-independent extracellular signal-regulated kinase-mediated pathway.     

Oligonucleotide lipoplexes: the influence of oligonucleotide composition on complexation.

Despite extensive investigations into oligonucleotide lipoplexes, virtually no work has addressed whether the physicochemical properties of these assemblies vary as a function of the constituent oligonucleotide (ODN) sequence and/or composition. The present study was aimed at answering this question. To this end, we complexed N-(1-(2,3-dioleoyloxy)propyl)-N,N,N-trimethylammonium chloride (DOTAP) liposomes, in dispersion, with either 18-mer phosphorothiote homo-oligonucleotides composed of either adenine, thymidine or cytosine; or one of three structurally related 18-mer phosphorothioate oligonucleotides (S-ODNs) (G3139, its reverse sequence and its two-base mismatch). After ODN addition to vesicles at different mole ratios, changes in pH and electrical surface potential at the lipid-water interface were analyzed by using the fluorophore heptadecyl-7-hydroxycoumarin while particle size distributions were analyzed by static-light scattering. The results indicate that each homo-oligonucleotide does indeed exhibit different complexation behavior. In particular, the maximal level of DOTAP neutralization by the polyadenine S-ODN is much lower than that for the two other homo-oligonucleotides and hence its lipoplex is much more positively charged. Much smaller electrostatic differences are also apparent between lipoplexes formed from each of the G3139-related ODNs. This paper identifies nucleotide base selection and sequence as a variable that can affect the physicochemical properties of oligonucleotide lipoplexes and hence probably their transfection competency.     

The Search for Meaning: Eventfulness in the Lives of Homeless Mentally Ill Persons in the Skid Row District of Los Angeles

In the past two decades, the field ofpsychiatry has seen the once dominantpsychoanalytic theories overtaken by biologicalexplanations and approaches to severe mentalillness. With this change in perspective, thesignificance of fantasies and delusions havebeen reduced to being merely symptoms ofpsychopathology rather than reflections ofhuman needs and motivations. Usingethnographic evidence from a long-term researchproject, this paper explores one method bywhich mentally ill homeless individuals in theSkid Row district of Los Angeles attempted towrest meaningful lives for themselves out of anenvironment that featured disaffiliation,violence, boredom, and extreme poverty.     

Studies on the participation of epididymal sperm protein DE/CRISP-1 in egg activation.

Protein DE (32 kDa) associates with sperm during epididymal maturation and participates in sperm-egg fusion through its binding to complementary sites on the egg surface. In the present work we investigated the participation of DE in two mechanisms probably involved in egg activation: the ability of DE to trigger activation by its interaction with the binding sites on the egg surface (receptor model) and its ability to regulate intracellular calcium channels (sperm factor model). The incubation of eggs with DE did not promote activation parameters such as calcium oscillations or meiosis resumption. Secondly, microinjection of DE into eggs was ineffective in either eliciting calcium release or modifying oscillations induced by an activating sperm extract. Together, these results argue against the participation of DE in egg activation, restricting the activity of this protein and its egg binding sites to the sperm-egg fusion process.     

Rab11 polarization of the Drosophila oocyte: a novel link between membrane trafficking, microtubule organization, and oskar mRNA localization and translation.

The Drosophila embryonic body plan is specified by asymmetries that arise in the oocyte during oogenesis. These asymmetries are apparent in the subcellular distribution of key mRNAs and proteins and in the organization of the microtubule cytoskeleton. We present evidence that the Drosophila oocyte also contains important asymmetries in its membrane trafficking pathways. Specifically, we show that alpha-adaptin and Rab11, which function critically in the endocytic pathways of all previously examined animal cells, are localized to neighboring compartments at the posterior pole of stage 8-10 oocytes. Rab11 and alpha-adaptin localization occurs in the absence of a polarized microtubule cytoskeleton, i.e. in grk null mutants, but is later reinforced and/or refined by Osk, the localization of which is microtubule dependent. Analyses of germline clones of a rab11 partial loss-of-function mutation reveal a requirement for Rab11 in endocytic recycling and in the organization of posterior membrane compartments. Such analyses also reveal a requirement for Rab11 in the organization of microtubule plus ends and osk mRNA localization and translation. We propose that microtubule plus ends and, possibly, translation factors for osk mRNA are anchored to posterior membrane compartments that are defined by Rab11-mediated trafficking and reinforced by Rab11-Osk interactions.     

KIN241: a gene involved in cell morphogenesis in Paramecium tetraurelia reveals a novel protein family of cyclophilin–RNA interacting proteins (CRIPs) conserved from fission yeast to man

In this study, we report cloning, by functional complementation of the KIN241 gene involved in Paramecium cell morphogenesis, cortical organization and nuclear reorganization. This gene is predicted to encode a protein of a novel type, comprising a cyclophilin-type, peptidyl-prolyl isomerase domain, an RNA recognition motif, followed by a region rich in glutamate and lysine (EK domain) and a C-terminal string of serines. As homologues of this protein are present in the genomes of Schizosaccharomyces pombe, Caenorhabditis elegans, Drosophila melanogaster, Arabidopsis thaliana and Homo sapiens, the Kin241p predicted sequence defines a new family of proteins that we propose to call 'CRIP', for cyclophilin-RNA interacting protein. We demonstrate that, in Paramecium, Kin241p is localized in the nucleus and that deletion of some nuclear localization signals (NLSs) decreases transport of the protein into the nucleus. No Kin241-1 protein is present in mutant cells, suggesting that the C-terminal serine-rich region is responsible for protein stability.     

FPs have vital role in ensuring success of breast cancer screening programs

SCREENING IS THE ONLY PROVEN STRATEGY for reducing breast cancer mortality in women older than 50. Over the last 9 years, 8 provinces and 2 (territories have established independent dedicated mammography programs. A recent workshop on screening programs was told that family physicians play a crucial role in the ultimate success of these programs because of their referral role.