Pseudonotohymena antarctica n. g., n. sp. (Ciliophora,Hypotricha), a New Species from Antarctic Soil

A new soil ciliate, Pseudonotohymena antarctica n. g., n. sp., from King George Island, Antarctica, is described based on live observation, protargol impregnation, and its 18S rRNA gene. The new genus Pseudonotohymena is morphologically similar to the genus Notohymena Blatterer and Foissner 1988 in the following characteristics: 18 fronto‐ventral‐transverse cirri, a flexible body, undulating membranes, dorsomarginal kineties, and the number of cirri in the marginal rows. However, Pseudonotohymena differs from Notohymena particularly in the dorsal ciliature, that is, in possessing a nonfragmented dorsal kinety (vs. fragmented). In addition, the molecular phylogenetic relationship of the new species differs from that of Notohymena species. On the basis of the morphological features, the genetic data, and morphogenesis, we establish P. antarctica n. g., n. sp. In addition, the cyst morphology of this species is described.     

Patterns of hybridization and population genetic structure in the terrestrial orchids Liparis kumokiri and Liparis makinoana (Orchidaceae) in sympatric populations

We investigated the potential for gene flow and genetic assimilation via hybridization between common and rare species of the terrestrial orchid genus Liparis, focusing specifically on sympatric and allopatric populations of the common Liparis kumokiri and the rare Liparis makinoana. We utilized analyses of genetic diversity, morphology, and the spatial distributions of individuals and genotypes to quantify the dynamics of interspecific gene flow at within- and among-population scales. High levels of allozyme genetic diversity (HE) were found in populations of the rare L. makinoana (0.317), whereas the common L. kumokiri (N = 1744 from 14 populations) revealed a complete lack of variation. This contrast may reflect different breeding systems and associated rates of genetic drift (L. makinoana is self-incompatible, whereas L. kumokiri is self-compatible). At the two known sympatric sites, individuals were found that recombined parental phenotypes, possessing floral characteristics of L. kumokiri and vegetative characteristics of L. makinoana. These putative hybrids were the only individuals found segregating alleles diagnostic of both parental species. Analysis of these individuals indicated that hybrid genotypes were skewed towards L. kumokiri and later generation recombinants of L. kumokiri at both sympatric sites. Furthermore, Ripley's bivariate L(r) statistics revealed that at one site these hybrids are strongly spatially clustered with L. kumokiri. Nonetheless, the relatively low frequency of hybrids, absence of ongoing hybridization (no F1s or first generation backcrossess), and strong genetic differentiation between morphologically 'pure' parental populations at sympatric sites (FST = 0.708-0.816) indicates that hybridization was not an important bridge for gene flow. The results from these two species suggest that natural hybridization has not played an important role in the diversification of Liparis, but instead support the view that genetic drift and limited gene flow are primarily responsible for speciation in Liparis. Based on genetic data and current status of the species, implications of the research for conservation are considered to provide guidelines for appropriate conservation and management strategies.     

Interleukin-10 enhances the oxidized LDL-induced foam cell formation of macrophages by antiapoptotic mechanisms

Interleukin (IL)-10 may have a therapeutic potential in atherosclerosis, but its mechanisms of action have not been clarified. Foam cell formation is a key event in atherogenesis, and apoptosis of these lipid-laden cells may promote plaque destabilization. We sought to explore whether IL-10 could have plaque-stabilizing properties in acute coronary syndromes (ACS). We studied the effect of IL-10 on oxidized low density lipoprotein (oxLDL)-stimulated THP-1 cells and monocyte-derived macrophages from ACS patients and healthy controls using different experimental approaches. Our main findings were: i) IL-10 enhances lipid accumulation in oxLDL-stimulated THP-1 macrophages, at least partly by counteracting oxLDL-induced apoptosis; ii) This antiapoptotic effect of IL-10 involves increased expression of the antiapoptotic genes Bfl-1 and Mcl-1, accompanied by protective effects on mitochondria function; iii) By silencing Bfl-1 and Mcl-1 genes using siRNAs, we were able to abolish this IL-10-mediated effect on lipid accumulation; iv) IL-10 also induced lipid accumulation in oxLDL-stimulated macrophages from patients with ACS, but not in macrophages from healthy controls; v) In ACS patients, this enhancing effect of IL-10 on lipid accumulation was accompanied by enhanced Mcl-1 expression. No such antiapoptotic effect was seen in macrophages from healthy controls. These findings suggest a new mechanism for the effect of IL-10 in atherosclerosis, possibly contributing to plaque stabilization.     

Going Where the Grass Is Greener: On the Study of Pastoral Mobility in Ferlo, Senegal

Based on a case study from Ferlo in Senegal, this paper discusses how pastoral mobility can be studied and understood with special emphasis on the use of GPS data. It has a dual objective: first, to investigate the methodological potential of using GPS data; second, to discuss the analytical use of GPS data for understanding mobility. The methodological potential for using GPS data is related to quantifying mobility and characterizing mobility patterns in space and time. Analytically, GPS data can be used in combination with qualitative information to make method triangulation. The GPS data can be used both prior to qualitative interviews to make informed questions about mobility and they can be used after qualitative investigations to illustrate points made or to reveal inconsistencies. The study shows that cattle walk about 5000 km per year (excluding night grazing) and different mobility patterns occur depending on the season. Issues such as the cattle complex and the notion of the independent, nomadic pastoralist are discussed in relation to pastoral mobility. Although cattle are of major importance to the Fulani, it is not important for them to walk with their animals, which are left to roam freely or supervised by paid herders. It is necessary to take into account all these issues if we want to go beyond the simple understanding of mobility as a means to find pasture and water.     

The prevalent use of contraception among teenagers in Denmark and the corresponding low pregnancy rate

In Denmark the number of births and induced abortions among teenagers has reduced and teenage parenthood is now rare. This paper evaluates the correlation between this observed fertility and reported sexual and contraceptive behaviour. In 1989 a sample of 16-20-year-olds in Denmark was selected at random and personally interviewed about sexual and contraceptive behaviour. Ninety-five per cent of the young women who had experienced sexual intercourse used contraception at the most recent sexual intercourse. In order to support the validity of this finding a model was developed to estimate an expected number of conceptions in the age groups concerned. The model included both the information on coital frequency and use of contraception from the questionnaire and available efficacy rates on contraception. The estimates derived by the model were compared with the registered number of births and induced abortions derived from public registers. The analysis revealed a high accordance between the estimated number of conceptions and the registered number of births and induced abortions for each age group. This underlines the validity of the data on sexual and contraceptive behaviour sampled among teenagers in Denmark. The findings indicate that contraceptive failure is a much greater problem than non-use of contraception for teenagers in Denmark.     

The protein-tyrosine phosphatase CD45 reaches the cell surface via golgi-dependent and -independent pathways

CD45 is a receptor protein-tyrosine phosphatase essential for T cell development and lymphocyte activation. It is highly glycosylated, with multiple isoforms and glycoforms expressed on the cell surface depending on the cell type and stage of differentiation. Interestingly, we found two pools of newly synthesized CD45 expressed on plasma membrane, one of which arrived by 5 min after synthesis. The remaining pool of CD45 was fully glycosylated and began to arrive at the cell surface at approximately 15 min. The rapidly expressed population of CD45 possessed exclusively endoglycosidase H-sensitive N-linked carbohydrate. Additionally, this rapidly expressed pool of CD45 appeared on the cell surface in a brefeldin A (BFA)-insensitive manner, suggesting that it reached the cell surface independent of the Golgi complex. The remaining CD45 trafficked through the Golgi complex, and transport proceeded via a BFA-sensitive mechanism. These data suggest that CD45 is able to reach the cell surface via two distinct routes. The first is a conventional Golgi-dependent pathway that allows fully processed CD45 to be expressed. The second utilizes an ill defined mechanism that is independent of the Golgi, is BFA-resistant, and allows for the expression of CD45 with immature carbohydrate on the cell surface.     

Apoptosis in activated rat pancreatic stellate cells

Proliferation and matrix synthesis by activated pancreatic stellate cells (PSC) participate in the development of chronic pancreatitis. Apoptosis of PSC may terminate this process but has not yet been studied in this particular cell type and was the aim of the present study. PSC were isolated from rat pancreas and characterized for expression of glial fibrillary acidic protein, alpha-smooth muscle actin, CD95, and tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) receptors. Apoptosis was determined by TdT-UTP nick end-labeling reaction, annexin V binding, and caspase-8 activation. Both CD95L and TRAIL induced apoptosis in PSC. The apoptotic response was minor in PSC cultured for 7 days but increased markedly thereafter. Sensitization of PSC with culture duration was accompanied by increased expression of CD95 and TRAIL receptor 2 and no alterations of Flip expression or protein kinase B phosphorylation but was paralleled by the appearance of a COOH-terminal cleavage product of receptor-interacting protein. PSC apoptosis was also induced by PK-11195, a ligand of the peripheral benzodiazepine receptor. PSC apoptosis may be important in terminating the wound-healing response after pancreas injury and exhibits features distinct from apoptosis induction in hepatic stellate cells.     

Allatostatins of the tiger prawn,Penaeus monodon (Crustacea: Penaeidea)

More than 40 peptides belonging to the -Y/FXFGL-NH(2) allatostatin superfamily have been isolated and identified from the central nervous system (CNS) of the tiger prawn, Penaeus monodon (Crustacea: Penaeidea). The peptides can be arranged in seven sub-groups according to the variable post-tyrosyl residue represented by Ala, Gly, Ser, Thr, Asn, Asp, and Glu. Two of the residues (Thr and Glu) have not been observed in this position previously in either insects or crustaceans. Also reported for the first time for allatostatins, two of the peptides are N-terminally blocked by a pyroglutamic acid residue. The yields of certain peptides with similar amino acid sequences to each other were, in some instances, very different. As an example, the yield of ANQYTFGL-NH(2) was 2pmol, compared with ASQYTFGL-NH(2), with a yield of 156 pmol. There are several possibilities to account for this. If, as in all species so far investigated, there is a single allatostatin gene in P. monodon, then it would appear that different sub-populations have contributed mutant forms of particular peptides to the extract. Another, less likely possibility is that this species has more than one allatostatin gene, producing a variable array of peptides albeit in different molar ratios. Several peptides were present apparently as a result of the loss of one or more residues at the N-terminus of a larger form, either due to N-terminal degradation or specific post-translational processing. The number of peptides identified exceeds that for any other insect or crustacean species previously investigated. None is identical to any of the 60-70 insect allatostatins so far identified, and only three are common to other crustaceans. Immunohistochemical study of the CNS of P. monodon, with the same antisera as used to monitor the purification, confirms the widespread nature and complexity of allatostatinergic neural pathways in arthropods. Thus, all neuromeres of the brain, and all except one of the ventral cord ganglia, possess allatostatin neurons and extensive areas of allatostatin-innervated neuropile. In addition to the cytological evidence that the allatostatins act as neurotransmitters, associated with tissues as varied as eyes and legs, their presence in neurohemal areas such as the sinus gland and the perineural sheath of the thoracic ganglia suggests a neuroendocrine function. As well as posing a challenge to physiologists assigning specific functions to the allatostatins, their extensive intra-species multiplicity, linked to their inter-species variability, also presents a complex problem to geneticists and evolutionists.     

Effects of heat and high-pressure treatments on antigenicity of beef extract

The sera of bovine gamma globulin (BGG) positive beef allergic patients were used in this study in order to investigate changes in IgE-specific binding activity with regard to beef extract altered by heat or high-pressure treatment. In inhibition-ELISA, the sample treated at 60 degrees C did not show any significant changes in the antigenicity of BGG, but the sample treated at 100 degrees C showed a decrease of the antigenicity. In the case of the treatment with heating at 100 degrees C, heat-coagulation occurred in the beef extract. The resulting supernatant and precipitate of the sample by centrifugation were analyzed by immunoblotting. Only the fraction of precipitate showed a specific binding activity with the sera. Based on this result, it was speculated that the persistent antigenicity found even after the treatment at 100 degrees C in inhibition-ELISA remained principally in the heat-coagulated fraction, which indicated the importance of the method of handling the heat-coagulation in heat treatment. High-pressure treatments (200 MPa-600 MPa) of beef extract did not show any significant changes in the binding with the sera.     

Proteomic strategies to reveal tumor heterogeneity among urothelial papillomas

Proteomics and immunohistochemistry were used to reveal tumor heterogeneity among urothelial papillomas (UPs) with the long term goal of predicting their biological potential in terms of outcome. First, we identified proteins that were deregulated in invasive fresh lesions as compared with normal urothelium, and thereafter we immunostained UPs with a panel of antibodies against some of the markers. Twenty-two major proteins showing variations of 2-fold or more in at least one-third of the invasive lesions were selected. Specific antibodies against several of the proteins were obtained, but only a few reacted positively in immunostaining. A panel consisting of antibodies against keratinocytes (CKs) 5, 13, 18, and 20 and markers of squamous metaplasia (CKs 7, 8, and 14) was used to probe normal urothelium and 30 UPs collected during a period of five years. Four UPs showed a normal phenotype, whereas the rest could be grouped in five major types that shared aberrant staining with the CK20 antibody. Type 1 heterogeneity (n = 4) showed preferred staining of the umbrella cells with the CK8 antibody. Type 2 (n = 11) was typified by the staining of the basal and intermediate layers with the CK20 antibody. Type 3 (n = 7) was characterized by the predominant staining of the basal cell layer with the CK5 antibody. Type 4 (n = 1) showed areas of CK7 negative cells, whereas type 5 (n = 3) showed loss of staining of the basal cells with the CK20. 29% of the patients experienced recurrences, but none progressed to invasive disease. Patients harboring phenotypic alterations in the basal cell compartment (types 3 and 5) showed the highest number of recurrences (4/7 and 2/3, respectively), and all type 3 lesions progressed to a higher degree of dedifferentiation. Even though a long term prospective study involving a larger sample size is required to assess the biological potential of these lesions, we believe that this approach will prove instrumental for revealing early phenotypic changes in different types of cancer.