Characterization and recruitment of plasmacytoid dendritic cells in synovial fluid and tissue of patients with chronic inflammatory arthritis

Dendritic cells (DCs) are thought to play a key role in driving the immunopathogenic response underlying chronic inflammatory arthritis. In this study, we have examined the presence and phenotype of plasmacytoid DCs (pDCs) in the synovial fluids (SF) of patients with rheumatoid arthritis (RA), psoriatic arthritis (PA), and osteoarthritis (OA) and determined the chemotactic properties of SF from these patients toward pDCs. Flow cytometry analysis showed that the percentage of pDCs, identified as a population of Lin(-)CD123(++) cells, is 4- to 5-fold higher in RA SF and PA SF than in OA SF. The morphological and immunophenotypic characterization of pDCs isolated from PA and RA SF indicates that they are in an immature state, most likely due to inhibitory factors present in RA SF, but are still able to undergo maturation when exposed ex vivo to viral agent or unmethylated DNA. CD123(+) and BDCA2(+) pDCs were detected by immunohistochemistry in RA synovial tissue in which expression of the IFN-alpha-inducible protein MxA was also found, suggesting production of type I IFN by maturing pDCs. We also show that CXCR3 and CXCR4 are expressed by both blood-derived pDCs and pDCs isolated from RA and PA SF and that CXCL-10, CXCL-11, and CXCL-12 present in RA and PA SF stimulate chemotaxis of blood-derived pDCs. Altogether, these findings suggest that chemokine-driven recruitment of pDCs from the blood to the inflamed synovium could be important in the regulation of the immune response in chronic inflammatory arthritis.     

A mathematical description of blood spiral flow in vessels: application to a numerical study of flow in arterial bending

Local arterial haemodynamics has been associated with the pathophysiology of several cardiovascular diseases. The stable spiral blood-flows that were observed in vivo in several vessels, may play a dual role in vascular haemodynamics, beneficial since it induces stability, reducing turbulence in the arterial tree, and accounts for normal organ perfusion, but detrimental in view of the imparted tangential velocities that are involved in plaque formation and development. Being a spiral flow considered representative of the local blood dynamics in certain vessels, a method is proposed to quantify the spiral structure of blood flow. The proposed function, computed along a cluster of particle trajectories, has been tested for the quantitative determination of the spiral blood flow in a three-dimensional, s-shaped femoral artery numerical model in which three degrees of stenosis were simulated in a site prone to atherosclerotic development. Our results confirm the efficacy of the Lagrangian analysis as a tool for vascular blood dynamics investigation. The proposed method quantified spiral motion, and revealed the progression in the degree of stenosis, in the presented case study. In the future, it could be used as a synthetic tool to approach specific clinical complications.     

Reduction of active elastase concentration by means of immobilized inhibitors: a novel therapeutic approach

The inhibitory power of three different active Nylon membranes, separately loaded with three different protease inhibitors, was studied with the aim of reducing the increased elastase concentration occurring during hemodialysis or extracorporeal blood circulation in patients undergoing cardiopulmonary bypass. Chemical grafting was carried out to make the inert Nylon membrane suitable for the immobilization of the inhibitors. The behavior of immobilized alpha(1)-antitrypsin, bovine pancreatic trypsin inhibitor (BPTI), or elastatinal was separately studied. alpha(1)-Antitrypsin and BPTI were covalently immobilized by means of a diazotization process, whereas elastatinal was covalently attached via a condensation process mediated by glutaraldehyde. The inhibitory power of each membrane type was studied as a function of the amount of immobilized inhibitor and temperature. All active membranes have shown good inhibitory power. The most efficient membrane was that loaded with alpha(1)-antitrypsin, the less efficient that with BPTI.     

Pyroglutamate-modified amyloid beta-peptides--AbetaN3(pE)--strongly affect cultured neuron and astrocyte survival

N-terminally truncated amyloid-beta (Abeta) peptides are present in early and diffuse plaques of individuals with Alzheimer's disease (AD), are overproduced in early onset familial AD and their amount seems to be directly correlated to the severity and the progression of the disease in AD and Down's syndrome (DS). The pyroglutamate-containing isoforms at position 3 [AbetaN3(pE)-40/42] represent the prominent form among the N-truncated species, and may account for more than 50% of Abeta accumulated in plaques. In this study, we compared the toxic properties, fibrillogenic capabilities, and in vitro degradation profile of Abeta1-40, Abeta1-42, AbetaN3(pE)-40 and AbetaN3(pE)-42. Our data show that fibre morphology of Abeta peptides is greatly influenced by the C-terminus while toxicity, interaction with cell membranes and degradation are influenced by the N-terminus. AbetaN3(pE)-40 induced significantly more cell loss than the other species both in neuronal and glial cell cultures. Aggregated AbetaN3(pE) peptides were heavily distributed on plasma membrane and within the cytoplasm of treated cells. AbetaN3(pE)-40/42 peptides showed a significant resistance to degradation by cultured astrocytes, while full-length peptides resulted partially degraded. These findings suggest that formation of N-terminally modified peptides may enhance beta-amyloid aggregation and toxicity, likely worsening the onset and progression of the disease.     

Epicardial Fat from Echocardiography: A New Method for Visceral Adipose Tissue Prediction

Objective: To validate transthoracic echocardiography as an easy and reliable imaging method for visceral adipose tissue (VAT) prediction. VAT is recognized as an important indicator of high cardiovascular and metabolic risk. Several methods are applied to estimate VAT, with different results. Research Methods and Procedures: We selected 60 healthy subjects (29 women, 31 men, 49.5 ± 16.2 years) with a wide range of body mass indexes. Each subject underwent transthoracic echocardiogram and magnetic resonance imaging (MRI) to measure epicardial fat thickness on the right ventricle. Measurements of epicardial adipose tissue thickness were obtained from the same echocardiographic and MRI views and points. MRI was also used to measure VAT cross‐sectional areas at the level of L4 to L5. Anthropometric indexes were also measured. Results: Subjects with predominant visceral fat accumulation showed higher epicardial adipose tissue thickness than subjects with predominant peripheral fat distribution: 9.97 ± 2.88 vs. 4.34 ± 1.98 (p = 0.005) and 7.19 ± 2.74 vs. 3.43 ± 1.64 (p = 0.004) in men and women, respectively. Simple linear regression analysis showed an excellent correlation between epicardial adipose tissue and waist circumference (r = 0.895, p = 0.01) and MRI abdominal VAT (r = 0.864, p = 0.01). Multiple regression analysis showed that epicardial adipose tissue thickness (r² = 0.442, p = 0.02) was the strongest independent variable correlated to MRI VAT. Bland test confirmed the good agreement between the two methods. Discussion: Epicardial adipose tissue showed a strong correlation with anthropometric and imaging measurements of VAT. Hence, transthoracic echocardiography could be an easy and reliable imaging method for VAT prediction.     

An ELISA-based procedure for assaying proteins in digests of human leukocytes and cell lines, using specifically selected peptides and appropriate antibodies

Background  

We describe the application of an ELISA-based assay (the Peptidomatrix) that can be used to simultaneously identify and quantitate a number of proteins in biological samples. The biological sample (blood component, biopsy, culture or other) is first lysed to release all the proteins, without any additional separation. The denatured proteins in the sample are then digested in bulk with the desired proteolytic enzyme(s). The peptides in the digest are then assayed by appropriate antibodies, using a competition ELISA protocol.     

Simultaneous determination of enantiomerization and hydrolysis kinetic parameters of chiral N‐alkylbenzothiadiazine derivatives

On‐column stopped flow multidimensional HPLC (sfMDHPLC) and dynamic high‐performance liquid chromatography were applied to investigate the influence of alkyl substituents at the sulfonamidic and amino moieties of benzothiadiazine 1,1‐dioxide derivatives on hydrolysis and enantiomerization rate constants. The data obtained indicate the presence of pyrrolo substituent at the 3,4 positions on benzothiadiazine rings inhibits the hydrolysis, whereas the enantiomerization occurs in acidic medium. Hydrolysis rates are quite similar for the two benzothiadiazines methyl substituted to nitrogen at 2‐ and 4‐positions. Conversely, enantiomerization rate of 4‐N‐methyl substituted is significantly higher than 2‐N‐methyl substituted. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont,and Associated Sex-Ratio Differences

The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed.     

An integrative approach to species discrimination in the Anagrus atomus group sensu stricto (Hymenoptera: Mymaridae), with a description of a new species

Egg parasitoids of the genus Anagrus Haliday (Hymenoptera: Mymaridae) are natural enemies of many pests around the world. We used an integrative approach to characterize some species belonging to the Anagrus atomus group, using specimens reared from leafhoppers infesting some Lamiaceae. Starting from morphological identifications based on available keys, we carried out a multi-locus genetic characterization using phylogenetic and species delimitation analyses, and integrated it with biological and morphometric evidence. This approach revealed the existence of a new species, A. nepetellae sp. nov., here described along with its phenological traits. The approach also allowed us to characterize the expected taxonomic stability of other putative species within the group. We propose two new species groups called the atomus group sensu stricto and the vilis group, with the goal of streamlining the taxonomy of the atomus group. We also present a key for the identification of females of the European species of the atomus group sensu stricto. Some specimens show heterozygosity in 28S-D2 sequences, suggesting hybridization between A. atomus and A. nepetellae, which, if it is common between other species as well, could partly explain the taxonomic problems in the genus Anagrus. DNA sequencing of specimens reared by the same biofactory at different times suggests involuntary contamination leading to the displacement of a laboratory strain of A. atomus by A. nepetellae, which may have resulted from undetected partial reproductive compatibility.http://zoobank.org/urn:lsid:zoobank.org:pub:DFCD7654-5AA5-4E4F-AE48-24377BAACEFE     

Recent Advances in the Synthesis of 6-Vinyl-N,N-Dialkylcytosine Derivatives

Abstract

A general, selective and efficient synthesis of N,N-dialkyl-cytosine derivatives bearing a vinyl moiety on the C-6 side chain is reported.