Spontaneous generation and survival of blood dendritic cells in mononuclear cell culture without exogenous cytokines

Studies on purified blood dendritic cells (DCs) are hampered by poor viability in tissue culture. We, therefore, attempted to study some of the interactions/relationships between DCs and other blood cells by culturing unseparated peripheral blood mononuclear cell (PBMC) preparations in vitro. Flow cytometric techniques were used to undertake a phenotypic and functional analysis of DCs within the cultured PBMC population. We discovered that both the CD11c(+) and CD11c(-) CD123(hi) DC subsets maintained their viability throughout the 3-day culture period, without the addition of exogenous cytokines. This viability was accompanied by progressive up-regulation of the surface costimulatory (CD40, CD80, CD86) and activation (CMRF-44, CMRF-56, CD83) molecules. The survival and apparent production of DCs in PBMC culture (without exogenous cytokines) and that of sorted DCs (with cytokines) were evaluated and compared by using TruCOUNT analysis. Absolute DC counts increased (for CD123hi and CD11c+ subsets) after overnight culture of PBMCs. Single-cell lineage depletion experiments demonstrated the rapid and spontaneous emergence of new in vitro generated DCs from CD14(+)/CD16(+) PBMC radioresistant precursors, additional to the preexisting ex vivo DC population. Unlike monocyte-derived DCs, blood DCs increased dextran uptake with culture and activation. Finally, DCs obtained after culture of PBMCs for 3 days were as effective as freshly isolated DCs in stimulating an allogeneic mixed leukocyte reaction. (C) 2002 by The American Society of Hematology.

Parallel simulation system for earthquake generation: Fault analysis modules and parallel coupling analysis

Solid earth simulations have recently been developed to address issues such as natural disasters, global environmental destruction and the conservation of natural resources. The simulation of solid earth phenomena involves the analysis of complex structures including strata, faults, and heterogeneous material properties. Simulation of the generation and cycle of earthquakes is particularly important, but such simulations require the analysis of complex fault dynamics. GeoFEM is a parallel finite-element analysis system intended for solid earth field phenomena problems. This paper describes recent development in the GeoFEM project for the simulation of earthquake generation and cycles.

Direction selectivity in the retina

The neuronal circuitry underlying the generation of direction selectivity in the retina has remained elusive for almost 40 years. Recent studies indicate that direction selectivity may be established within the radial dendrites of 'starburst' amacrine cells and that retinal ganglion cells may acquire their direction selectivity by the appropriate weighting of excitatory and inhibitory inputs from starburst dendrites pointing in different directions. If so, this would require unexpected complexity and subtlety in the synaptic connectivity of these CNS neurons.

Morphology, ultrastructure, and implied function of ciliated sensory structures on the developmental stages of Merizocotyle icopae (Monogenea : Monocotylidae)

Experimental infections were used to track the fate of the dorsal sensilla of Merizocotyle icopae (Monogenea: Monocotylidae) from nasal tissue of the shovelnose ray, Rhinobatos typus (Rhinobatidae). Scanning and transmission electron microscopy revealed that 3 types of uniciliate dorsal sensilla exist at different times in the development of the monogenean. Type 1 sensilla have little or no invagination where the cilium exits the distal end of the dendrite and possess a ring of epidermis surrounding the cilium distal to the invagination. Type 2 sensilla have a deep invagination where the cilium exits the dendrite. Type 3 sensilla can be distinguished from the other types by the shape of the dendrite. The larvae have predominantly Type I dorsal sensilla, most of which are lost approximately 24 h after infection and a few Type 2 sensilla, which are retained. Additional Type 2 sensilla (termed Adult Type 2 sensilla), which are slightly different morphologically from the Type 2 sensilla of the larvae, form in later stages of development. Numerous Type 3 sensilla are unique to the dorsal surface of adults. Loss of all Type I sensilla upon attachment to the host, R. typus, suggests that these may be chemo- or mechanoreceptors responsible for host location by the swimming infective larvae. Type 2 sensilla appear to be important in the larvae, juveniles, and adults whereas the modality mediated by Type 3 is specific to adults. (C) 2003 Wiley-Liss, Inc.

Generation of CTL responses using Kunjin replicon RNA

The Kunjin replicon was used to express a polytope that consisted of seven hepatitis C virus cytotoxic T lymphocyte epitopes and one influenza cytotoxic T lymphocyte epitope for vaccination studies. The self-replicating nature of, and expression from, the ribonucleic acid was confirmed in vitro . Initial vaccinations with one dose of Kun-Poly ribonucleic acid showed that an influenza-specific cytotoxic T lymphocyte response was elicited more efficiently by intradermal inoculation compared with intramuscular delivery. Two micrograms of ribonucleic acid delivered in the ear pinnae of mice was sufficient to elicit a detectable cytotoxic T lymphocyte response 10 days post-vaccination. Further vaccination studies showed that four of the seven hepatitis C virus cytotoxic T lymphocyte epitopes were able to elicit weak cytotoxic T lymphocyte responses whereas the influenza epitope was able to elicit strong, specific cytotoxic T lymphocyte responses following three doses of Kun-Poly ribonucleic acid. These studies vindicate the use of the Kunjin replicon as a vector to deliver encoded proteins for the development of cell-mediated immune responses.

An approach to verifying and debugging simulation models governed by ordinary differential equations: Part 1. Methodology for residual generation

For dynamic simulations to be credible, verification of the computer code must be an integral part of the modelling process. This two-part paper describes a novel approach to verification through program testing and debugging. In Part 1, a methodology is presented for detecting and isolating coding errors using back-to-back testing. Residuals are generated by comparing the output of two independent implementations, in response to identical inputs. The key feature of the methodology is that a specially modified observer is created using one of the implementations, so as to impose an error-dependent structure on these residuals. Each error can be associated with a fixed and known subspace, permitting errors to be isolated to specific equations in the code. It is shown that the geometric properties extend to multiple errors in either one of the two implementations. Copyright (C) 2003 John Wiley Sons, Ltd.

Generation of aldehyde-derived protein modifications in ethanol-exposed heart

Background: Although excessive ethanol consumption is known to lead to a variety of adverse effects in the heart, the molecular mechanisms of such effects have remained poorly defined. We hypothesized that posttranslational covalent binding of reactive molecular species to proteins occurs in the heart in response to acute ethanol exposure. Methods: The generation of protein adducts with several aldehydic species was examined by using monospecific antibodies against adducts with malondialdehyde (MDA), acetaldehyde (AA), MDA-AA hybrids, and hydroxyethyl radicals. Specimens of heart tissue were obtained from rats after intraperitoneal injections with alcohol (75 mmol/kg body weight) with or without pretreatment with cyanamide (0.05 mmol/kg body weight), an aldehyde dehydrogenase inhibitor. Results: The amounts of MDA and unreduced AA adducts were found to be significantly increased in the heart of the rats treated with ethanol, cyanamide, or both, whereas no other adducts were detected in statistically significant quantities. Immunohistochemical studies for characterization of adduct distribution revealed sarcolemmal adducts of both MDA and AA in the rats treated with ethanol and cyanamide in addition to intracellular adducts, which were also present in the group treated with ethanol alone. Conclusions: These findings support the role of enhanced lipid peroxidation and the generation of protein-aldehyde condensates in vivo as a result of excessive ethanol intake. These findings may have implications in the molecular mechanisms of cardiac dysfunction in alcoholics.