Design of custom-shaped vascularized tissues using microtissue spheroids as minimal building units

Tissue engineering strategies are gathering clinical momentum in regenerative medicine and are expected to provide excellent opportunities for therapy for difficult-to-treat human pathologies. Being aware of the requirement to produce larger artificial tissue implants for clinical applications, we used microtissues, produced using gravity-enforced self-assembly of monodispersed primary cells, as minimal tissue units to generate scaffold-free vascularized artificial macrotissues in custom-shaped agarose molds. Mouse myoblast, pig and human articular-derived chondrocytes, and human myofibroblast (HMF)-composed microtissues (microm3 scale) were amalgamated to form coherent macrotissue patches (mm3 scale) of a desired shape. Macrotissues, assembled from the human umbilical vein endothelial cell (HUVEC)-coated HMF microtissues, developed a vascular system, which functionally connected to the chicken embryo's vasculature after implantation. The design of scaffold-free vascularized macrotissues is a first step toward the scale-up and production of artificial tissue implants for future tissue engineering initiatives.

Proposed minimal standards for the description of genera, species and subspecies of the Pasteurellaceae

Principles and guidelines are presented to ensure a solid scientific standard of papers dealing with the taxonomy of taxa of Pasteurellaceae Pohl 1981. The classification of the Pasteurellaceae is in principle based on a polyphasic approach. DNA sequencing of certain genes is very important for defining the borders of a taxon. However, the characteristics that are common to all members of the taxon and which might be helpful for separating it from related taxa must also be identified. Descriptions have to be based on as many strains as possible (inclusion of at least five strains is highly desirable), representing different sources with respect to geography and ecology, to allow proper characterization both phenotypically and genotypically, to establish the extent of diversity of the cluster to be named. A genus must be monophyletic based on 16S rRNA gene sequence-based phylogenetic analysis. Only in very rare cases is it acceptable that monophyly can not be achieved by 16S rRNA gene sequence comparison. Recently, the monophyly of genera has been confirmed by sequence comparison of housekeeping genes. In principle, a new genus should be recognized by a distinct phenotype, and characters that separate the new genus from its neighbours should be given clearly. Due to the overall importance of accurate classification of species, at least two genotypic methods are needed to show coherence and for separation at the species level. The main criterion for the classification of a novel species is that it forms a monophyletic group based on 16S rRNA gene sequence-based phylogenetic analysis. However, some groups might also include closely related species. In these cases, more sensitive tools for genetic recognition of species should be applied, such as DNA-DNA hybridizations. The comparison of housekeeping gene sequences has recently been used for genotypic definition of species. In order to separate species, phenotypic characters must also be identified to recognize them, and at least two phenotypic differences from existing species should be identified if possible. We recommend the use of the subspecies category only for subgroups associated with disease or similar biological characteristics. At the subspecies level, the genotypic groups must always be nested within the boundaries of an existing species. Phenotypic cohesion must be documented at the subspecies level and separation between subspecies and related species must be fully documented, as well as association with particular disease and host. An overview of methods previously used to characterize isolates of the Pasteurellaceae has been given. Genotypic and phenotypic methods are separated in relation to tests for investigating diversity and cohesion and to separate taxa at the level of genus as well as species and subspecies.

Minimal extracorporeal circulation is a promising technique for coronary artery bypass grafting

BACKGROUND: Minimal extracorporeal circulation (MECC) is a promising perfusion technology, taking the advantage of an ECC while having a significantly reduced priming volume. We analyzed the actual possible benefits of using MECC in patients undergoing CABG procedures and compared the results with conventional extracorporeal circulation (CECC). METHODS: One thousand fifty-three consecutive patients underwent CABG surgery using the MECC perfusion technique. Subgroup analyses focused on perioperative myocardial markers (cardiac troponin I [cTnI]), incidence of atrial fibrillation (AF), and perioperative evaluation of inflammatory markers and data were compared with those of patients who underwent CABG using CECC. A propensity score analysis was performed. RESULTS: Patient characteristics and distribution of EuroSCORE risk were similar in both groups. Severity of coronary artery disease and extent of revascularization were also comparable in both groups (number of distal anastomoses: 3.2 +/- 1.1 in CECC vs 3.2 +/- 0.9 in MECC; p = not significant [ns]). The cTnI was significantly lower in the MECC group (11.0 +/- 10.8 microg/L in MECC vs 24.7 +/- 25.3 microg/L in CECC; p < 0.05). Incidence of AF was 11.1% in MECC and 39.0% in CECC (p < 0.05). Inflammatory markers (interleukin-6, SC5b-9) were lower in MECC patients (p < 0.05). Propensity score analysis confirmed faster recovery in MECC patients and lower incidence of AF. CONCLUSIONS: Minimal extracorporeal circulation is a safe perfusion technique for CABG and may therefore concurrence OPCAB and traditional CABG under CECC.

Minimal assumption derivation of a weak Clauser-Horne inequality

According to Bell's theorem a large class of hidden-variable models obeying Bell's notion of local causality (LC) conflict with the predictions of quantum mechanics. Recently, a Bell-type theorem has been proven using a weaker notion of LC, yet assuming the existence of perfectly correlated event types. Here we present a similar Bell-type theorem without this latter assumption. The derived inequality differs from the Clauser-Horne inequality by some small correction terms, which render it less constraining.

Partial overlap of anti-mycobacterial, and anti-Saccharomyces cerevisiae mannan antibodies in Crohn's disease

AIM: To test whether humoral immune reaction against mycobacteria may play a role in anti-Saccharomyces cerevisiae antibodies (ASCA) generation in Crohn's disease (CD) and/or whether it correlates with clinical subtypes. METHODS: The dominant ASCA epitope was detected by Galanthus nivalis lectin (GNL)-binding assay. ASCA and IgG against mycobacterial lysates (M avium, M smegmatis, M chelonae, M bovis BCG, M avium ssp. paratuberculosis (MAP)] or purified lipoarabinomannans (LAM) were detected by ELISA. ASCA and anti-mycobacterial antibodies were affinity purified to assess cross-reactivities. Anti-mycobacterial IgG were induced by BCG-infection of mice. RESULTS: GNL bound to different extents to mycobacterial lysates, abundantly to purified mannose-capped (Man) LAM from M tuberculosis, but not to uncapped LAM from M smegmatis. Fifteen to 45% of CD patients but only 0%-6% of controls were seropositive against different mycobacterial antigens. Anti-mycobacterial IgG correlated with ASCA (r = 0.37-0.64; P = 0.003-P < 0.001). ASCA-positivity and deficiency for mannan-binding lectin synergistically associated with anti-mycobacterial IgG. In some patients, anti-mycobacterial antibodies represent cross-reactive ASCA. Vice-versa, the predominant fraction of ASCA did not cross-react with mycobacteria. Finally, fistulizing disease associated with antibodies against M avium, M smegmatis and MAP (P = 0.024, 0.004 and 0.045, respectively). CONCLUSION: Similar to ASCA, seroreactivity against mycobacteria may define CD patients with complicated disease and a predisposition for immune responses against ubiquitous antigens. While in some patients anti-mycobacterial antibodies strongly cross-react with yeast mannan; these cross-reactive antibodies only represent a minor fraction of total ASCA. Thus, mycobacterial infection unlikely plays a role in ASCA induction.