CD271 as a marker to identify mesenchymal stem cells from diverse sources before culture

Mesenchymal stem cells, due to their characteristics are ideal candidates for cellular therapy. Currently, in culture these cells are defined by their adherence to plastic, specific surface antigen expression and multipotent differentiation potential. However, the in vivo identification of mesenchymal stem cells, before culture, is not so well established. Pre-culture identification markers would ensure higher purity than that obtained with selection based on adherence to plastic. Up until now, CD271 has been described as the most specific marker for the characterization andpurification of human bone marrow mesenchymal stem cells. This marker has been shown to be specifically expressed by these cells. Thus, CD271 has been proposed as a versatile marker to selectively isolated and expand multipotent mesenchymal stem cells with both immunosuppressive and lymphohematopoietic engraftment-promoting properties. This review focuses on this marker, specifically on identification of mesenchymal stem cells from different tissues. Literature revision suggests that CD271 should not be defined as a universal marker to identify mesenchymal stem cells before culture from different sources. In the case of bone marrow or adipose tissue, CD271 could be considered a quite suitable marker; however this marker seems to be inadequate for the isolation of mesenchymal stem cells from other tissues such as umbilical cord blood or wharton’s jelly among others.     

Expression of recombinant organophosphorus hydrolase in the original producer of the enzyme,Sphingobium fuliginis ATCC 27551

The plasmid encoding His-tagged organophosphorus hydrolase (OPH) cloned from Sphingobium fuliginis was modified to be transferred back to this bacterium. The replication function of S. amiense plasmid was inserted at downstream of OPH gene, and S. fuliginis was transformed with this plasmid. The transformant produced larger amount of active OPH with His-tag than E. coli.     

“Sensory Switching” in Elbow Reconstruction

In the treatment of the soft tissue defect of the elbow, flap reconstruction is necessitated in many cases because of thinness of soft tissue at this region. In addition, reacquirement of tactile sensation is desirable because of the anatomical and specific functions of the elbow. Of three cases treated for elbow defects, one was reconstructed with a pedicled island forearm flap containing the lateral cutaneous nerve of the forearm, another was reconstructed with a venoneuro-accompanying artery fasciocutaneous flap (VNAF flap) containing the basilic vein, and the third with the VNAF flap containing the cephalic vein. The three cases demonstrated a sudden change of sensory territory 4 to 6 months after surgery, which was confirmed by touching the reconstructed region with patients'' eye-closed: from its original territory to the elbow in a “switching”-like action. Here we describe and discuss the concept of “sensory switching.”     

Magnetic susceptibilities of lake sediment and soils on the shoreline of Lake Naivasha,Kenya

On steep, unvegetated slopes, sands (particle sizes 0.063 to 2 mm) and gravels (2–64 mm) erode from the shoreline of Lake Naivasha (Kenya) and enter the lake basin. This occurred freely where fringing papyrus (Cyperus papyrus) swamp had been cleared in favour of landing jetties or agriculture. Gravel-sized particles have been recovered up to 60 m offshore and sands to 80 m. In an area where papyrus was undisturbed and the swamp margin was 52 m wide, gravel did not enter the lake and sands penetrated to around 35 m. Large particles are much easier to trace to source and to manage than the finer silts and clays (<0.63 m) that form the bulk of Lake Naivasha's sediment. The pattern of mass specific magnetic susceptibilities for the <63 m fraction of lake sediment around the southern shoreline of the lake suggests that fine particles enter open water directly from the shoreline and are not transported from the lake's only perennial inflow, the River Malewa in the north. Such particles originate from a hinterland that supports high intensity horticulture and are therefore a potential source of contamination. Mean ± SD susceptibility (_If) immediately offshore papyrus fringe was 0.49 ± 0.08 × 10^-6 m³ kg^-1 compared with higher values of 1.33 ± 0.14 × 10^-6 m³ kg^-1 where there was no papyrus barrier (P<0.0001). The value for five sites in the middle parts of the lake was 0.45 ± 0.02 × 10^-6 m³ kg^-1 with 1.38 ± 0.10 × 10^-6 m³ kg^-1 near the mouth of the River Malewa. The results of this study are evidence, therefore, that conservation of a continuous papyrus margin of about 50 m width is a priority for intercepting particulate material.     

Optimum concentration and pH of phosphate buffer for assay of cytochrome c oxidase in intact plant mitochondria

For measurement of cytochrome c oxidase activity in intact plant mitochondria the optimum concentration of K-Pi buffer and pH in the reaction was found to be 75 mM and 7.4 respectively. The suitable concentration of K-Pi buffer for suspending and storing mitochondria, however, was found to be 20 mM or lower. These requirements applied equally well for mitochondria from wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), maize (Zea mays L.), and snap bean (Phaseolus vulgaris L.).     

Action mechanism of tachyplesin I and effects of PEGylation

PEGylation of protein and peptide drugs is frequently used to improve in vivo efficacy. We investigated the action mechanism of tachyplesin I, a membrane-acting cyclic antimicrobial peptide from Tachypleus tridentatus and the effects of PEGylation on the mechanism. The PEGylated peptide induced the leakage of calcein from egg yolk l-α-phosphatidylglycerol/egg yolk l-α-phosphatidylcholine large unilamellar vesicles similarly to the parent peptide. Both peptides induced lipid flip-flop coupled to leakage and was translocated into the inner leaflet of the bilayer, indicating that tachyplesin I forms a toroidal pore and that PEGylation did not alter the basic mechanism of membrane permeabilization of the parent peptide. Despite their similar activities against model membranes, the peptides showed very different biological activities. The cytotoxicity of tachyplesin I was greatly reduced by PEGylation, although the antimicrobial activity was significantly weakened. We investigated the enhancement of the permeability of inner membranes induced by the peptides. Our results suggested that outer membranes and peptidoglycan layers play an inhibitory role in the permeation of the PEG moiety. Furthermore, a reduction in DNA binding by PEGylation may also contribute to the weak activity of the PEGylated peptide.     

Acidic extracellular pH induces p120-catenin-mediated disruption of adherens junctions via the Src kinase-PKCδ pathway

An acidic microenvironment induces disruption of adherens junctions (AJs) of hepatoma cells. This study investigated the impact of an acidic extracellular pH (pHe) on p120-catenin (p120-ctn) serine phosphorylation. pH 6.6 treatment increased intracellular calcium levels, activated protein kinase C (PKC)α and PKCδ, and decreased serine phosphorylation of p120-ctn. Further knockdown of PKCα and δ by small interference RNA (siRNA) prevented the pH 6.6-induced downregulation of p120-ctn at AJ and the serine dephosphorylation of p120-ctn. Moreover, PP2 pretreatment and siRNA of c-Src abrogated the pH 6.6-induced PKCδ activation. Together, the c-Src-PKCδ cascade and PKCα regulate the acidic pHe-induced AJ disruption.     

Fine structure of the ventral nerve centre and interspecific identification of individual neurons in the enigmatic Chaetognatha

The enigmatic arrow worms (Chaetognatha) are marine carnivores and among the most abundant planktonic organisms. Their phylogenetic position has been heavily debated for a long time. Most recent molecular studies still provide a diverging picture and suggest arrow worms to be some kind of basal protostomes. In an effort to understand the organization of the nervous system in this clade for a broad comparison with other Metazoa we analysed the ultrastructure of the ventral nerve centre in Spadella cephaloptera by transmission electron microscopy. We were able to identify six different types of neurons in the bilateral somata clusters by means of the cytoplasmic composition (regarding the structure of the neurite and soma including the shape and eu-/heterochromatin ratio within the nucleus) as well as the size and position of these neurons. Furthermore, our study provides new insights into the neuropil composition of the ventral nerve centre and several other fine structural features. Our second goal was to examine if individually identifiable neurons are present in the ventral nerve centres of four chaetognath species, Sagitta setosa, Sagitta enflata, Pterosagitta draco, and Spadella cephaloptera. For that purpose, we processed whole mount specimens of these species for immunolocalization of RFamide-related neuropeptides and analysed them with confocal laser-scanning microscopy. Our experiments provide evidence for the interspecific homology of individual neurons in the ventral nerve centres of these four chaetognath species suggesting that the potential to generate serially arranged neurons with individual identities is part of their ground pattern.     

Synthesis of monooxime-monocarbamoyl bispyridinium compounds bearing (E)-but-2-ene linker and evaluation of their reactivation activity against tabun- and paraoxon-inhibited acetylcholinesterase

Six AChE monooxime-monocarbamoyl reactivators with an (E)-but-2-ene linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and insecticide paraoxon was tested in vitro. The reactivation efficacies of pralidoxime, HI-6, obidoxime, K048, K075 and the newly prepared reactivators were compared. According to the results obtained, one reactivator seems to be promising against tabun-inhibited AChE and two reactivators against paraoxon-inhibited AChE. The best results were obtained for bisquaternary substances with at least one oxime group in position four.     

Isolated neurosecretory nerve endings as a tool for studying the mechanism of stimulus-secretion coupling

In the present paper we discuss the properties of a recently developed preparation of isolated neurosecretory nerve endings obtained from the rate neurohypophysis. These nerve terminals release two neurohormones, oxytocin and vasopressin, which are easily assayed by radioimmunoassay. Depolarization-induced secretion is dependent on the same parameters as those regulating release from the whole neural lobe. The isolated nerve endings can be permeabilized by means of digitonin; a treatment which gives direct access to the cytoplasm allowing the study of the minimal requirements for inducing neuropeptide release. Furthermore, some nerve endings are large enough to allow the use of the patch-clamp technique. In the present paper we present evidences which show that the isolated neurohypophysial nerve terminals represent a protent tool for studying the mechanism of stimulus-secretion.