Development of a cell with dendritic morphology from a precursor of B lymphocyte lineage

Cells developing dendritic morphology were detected in cultures of highly purified human B cells incubated with 4 beta-phorbol 12-myristate 13-acetate (PMA). After 72 hr of culture, 2 to 7% of the cells had assumed a dendritic shape provided that contact with a plastic or glass surface also occurred. Dendritic cells developed in cultures of B cells prepared by positively selecting cells that stained with the B cell-specific monoclonal antibody B1 with the fluorescence-activated cell sorter. By contrast, dendritic cells could not be detected in cultures of cells obtained from patients with Bruton's type agammaglobulinemia that lacked B cells. Cells with dendritic morphology were nonspecific esterase negative and not phagocytic. They expressed HLA-DR, DQ, and DP antigens, receptors for interleukin 2 and transferrin, and were stained by B1 and 60.3, an antibody that identifies the beta-chain common to lymphocyte function associated antigen-1, complement receptor 3, and the p150,95 antigen, but not by monoclonal antibodies to monocytes, complement receptors 2 or 3, NK cells, T cells, or Langerhans' cells. Formation of dendritic cells was inhibited by microtubule poisons (vinblastine, colchicine), a microfilament inhibitor (cytochalasin B), and the 60.3 monoclonal antibody, but not by inhibition of DNA synthesis. These data indicate that a subset of B cells is capable of assuming dendritic morphology after stimulation with phorbol esters and attachment to a surface. These dendritic cells exhibit characteristics that are quite similar to the interdigitating cells found in T cell-dependent areas of lymph nodes.     

A High‐fat vs. a Moderate‐fat Meal in Obese Boys: Nutrient Balance,Appetite, and Gastrointestinal Hormone Changes

Meal composition is a contributing factor to fat gain. In this study, we investigated the relationship between postprandial nutrient balance, satiety, and hormone changes induced by a high‐fat meal vs. a moderate‐fat meal. Ten prepubertal obese boys (BMI z‐score range: 1.3–3.0) were recruited. Two meals (energy: 590 kcal) were compared: (i) high‐fat (HF) meal: 12% protein, 52% fat, 36% carbohydrates; (ii) moderate‐fat (MF) meal: 12% protein, 27% fat, 61% carbohydrates. Pre‐ and postprandial (5 h) substrate oxidation (indirect calorimetry), appetite (visual analogue scale), biochemical parameters and gastrointestinal hormone concentrations were measured. Carbohydrate balance was significantly (P < 0.001) lower (31.3 (5.7) g/5 h vs. 66.9 (5.9) g/5 h) and fat balance was significantly (P < 0.001) higher (11.5 (3.3) g/5 h vs. ?0.7 (2.9) g/5 h) after HF than MF meal. Appetite (area under the curve (AUC)) was significantly reduced after an MF than an HF meal (494 (55) cm·300 min vs. 595 (57) cm·300 min, P < 0.05). Postprandial triglyceride concentration (AUC) was significantly (P < 0.05) higher after an HF than an MF meal: 141.1 (30.3) mmol·300 min/l vs. 79.3 (23.8) mmol·300 min/l, respectively. Peptide YY (PYY), cholecystokinin (CCK), and ghrelin concentrations (AUC) were not significantly different after an HF and MF meal. Glucagon‐like peptide‐1 (GLP‐1) was significantly (P < 0.05) higher after an HF than after an MF meal (72.3 (9.8) ng/ml vs. 22.7 (7.6) ng/ml, respectively), but it did not affect subjective appetite. In conclusion, an MF meal induced a better postprandial metabolic nutrient balance, triglyceride levels, and appetite suppression than an HF meal. Gastrointestinal hormones were not related to clinically assessed hunger suppression after both meals.     

Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose

Botryosphaeran (EPS_FRU), an exopolysaccharide of the β-(1→3,1→6)-d-glucan type with 31% branching at C-6, is produced by the fungus Botryosphaeria rhodina MAMB-05 when grown on fructose as carbon source. Botryosphaeran was derivatized by sulfonation to induce anticoagulant activity. The effectiveness of the sulfonation reaction by chlorosulfonic acid in pyridine was monitored by the degree of substitution and FT-IR analysis of the sulfonated EPS_FRU (once sulfonated, EPS_FRU SULF; and re-sulfonated, EPS_FRU RESULF). Activated partial thromboplastin time (APTT) and thrombin time (TT) tests of EPS_FRU RESULF indicated significant in vitro anticoagulant activity that was dose-dependent. EPS_FRU did not inhibit any of the coagulation tests.     

MegaSNPHunter: a learning approach to detect disease predisposition SNPs and high level interactions in genome wide association study

Background  

The interactions of multiple single nucleotide polymorphisms (SNPs) are highly hypothesized to affect an individual's susceptibility to complex diseases. Although many works have been done to identify and quantify the importance of multi-SNP interactions, few of them could handle the genome wide data due to the combinatorial explosive search space and the difficulty to statistically evaluate the high-order interactions given limited samples.     

Diversity of lactic acid bacteria of the bioethanol process

Background  

Bacteria may compete with yeast for nutrients during bioethanol production process, potentially causing economic losses. This is the first study aiming at the quantification and identification of Lactic Acid Bacteria (LAB) present in the bioethanol industrial processes in different distilleries of Brazil.     

Isolation and characterization of lymphatic microvascular endothelial cells from human tonsils

Human lymphatic endothelial cells (LECs) have isolated prevalently from human derma and tumors. As specialized lymphatic organs within the oropharynx, palatine tonsils are easily obtained and rich in lymphatic venules. Using a two-step purification method based on the sorting of endothelial cells with Ulex Europaeus Agglutinin 1 (UEA-1)-coated beads, followed by purification with monoclonal antibody D2-40, we successfully purified LECs from human palatine tonsils. The LECs were expanded on flasks coated with collagen type 1 and fibronectin for up to 8-10 passages and then analyzed for phenotypic and functional properties. Cultured cells retained the phenotypic pattern of the lymphatic endothelium of palatine tonsils and expressed functional VEGFR-3 molecules. In fact, stimulation with VEGFR-3 ligand, the vascular endothelium grow factor C, induced a marked increase in cell proliferation. Similarly to blood endothelial cells (BECs), LECs were able to form tube-like structure when seeded in Cultrex basement membrane extract. Comparative studies performed on LECs derived from palatine tonsils and iliac lymphatic vessels (ILVs), obtained with the same procedures, showed substantial discrepancies in the expression of various lymphatic markers. This points to the existence of micro- and macrovessel-derived LECs with different phenotypes, possibly involving different biological activities and functions. Palatine tonsil- and ILV-derived LECs may, therefore, represent new models for investigating function and biochemical properties of these lymphatic endothelia.     

The N Domain of Human Angiotensin-I-converting Enzyme: THE ROLE OF N-GLYCOSYLATION AND THE CRYSTAL STRUCTURE IN COMPLEX WITH AN N DOMAIN-SPECIFIC PHOSPHINIC INHIBITOR, RXP407*

Angiotensin-I-converting enzyme (ACE) plays a critical role in the regulation of blood pressure through its central role in the renin-angiotensin and kallikrein-kinin systems. ACE contains two domains, the N and C domains, both of which are heavily glycosylated. Structural studies of ACE have been fraught with severe difficulties because of surface glycosylation of the protein. In order to investigate the role of glycosylation in the N domain and to create suitable forms for crystallization, we have investigated the importance of the 10 potential N-linked glycan sites using enzymatic deglycosylation, limited proteolysis, and mass spectrometry. A number of glycosylation mutants were generated via site-directed mutagenesis, expressed in CHO cells, and analyzed for enzymatic activity and thermal stability. At least eight of 10 of the potential glycan sites are glycosylated; three C-terminal sites were sufficient for expression of active N domain, whereas two N-terminal sites are important for its thermal stability. The minimally glycosylated Ndom389 construct was highly suitable for crystallization studies. The structure in the presence of an N domain-selective phosphinic inhibitor RXP407 was determined to 2.0 Å resolution. The Ndom389 structure revealed a hinge region that may contribute to the breathing motion proposed for substrate binding.     

Identification of the first non-peptidic small molecule inhibitor of the c-Abl/14-3-3 protein–protein interactions able to drive sensitive and Imatinib-resistant leukemia cells to apoptosis

An in silico structure-based ligand design approach resulted in the identification of the first non-peptidic small molecule able to inhibit protein–protein interactions between 14-3-3 and c-Abl. This compound shows an anti-proliferative effect on human leukemia cells either sensitive or resistant to Imatinib, in consequence of the T315I mutation. It also mediates c-Abl release from 14-3-3 in a way similar to that found in response to Imatinib treatment.