Graphical lung analysis and simulation environment.

S Bosan; T R Harris

doi:10.1016/0169-2607(96)01722-1

Home/Archive/PubMed

PubMed · 8800608

Graphical lung analysis and simulation environment.

S Bosan·T R Harris

View original source ↗Export metadata ↓

Abstract

The study of transport across the pulmonary vasculature is an important aspect of the study of the lung. Models have often been used in conjunction with experimental work to further the information which can be obtained from experimental work alone. GLANSE was developed as an environment to carry out such analysis on microcomputers. The main model employed is a three region, homogeneous model which includes provisions for tracer diffusion in the extravascular region, hydrophilic and lipophyilic tracers as well as physiological parameters such as blood flow. Several heterogeneous models based on simplified versions of the three region model as well as two models which are not related to the three region model are also included. Computationally efficient routines for model simulations are used so as to enable their execution on microcomputers with large data sets. In addition, several methods for models analysis, such as parameter sensitivity and curve-fitting, as well as statistical analysis of results are also included. GLANSE has been tested and has been in use for several years for routine analysis of experimental data.

Explore related subjects

Biological Transport, Active Biometry Capillaries Computer Simulation Data Interpretation, Statistical Evaluation Studies as Topic Humans Lung Microcomputers Models, Biological Models, Statistical Pulmonary Circulation Regression Analysis Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

S Bosan, T R Harris. 1996. Graphical lung analysis and simulation environment.. https://doi.org/10.1016/0169-2607(96)01722-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

A cholesterol-regulated PP2A/HePTP complex with dual specificity ERK1/2 phosphatase activity.

The acute depletion of membrane cholesterol causes the concentration of pERK1/2 in caveola/raft lipid domains and the cytosol of human fibroblasts to dramatically increase. This increase could be caused by either the activation of MEK-1 or the inhibition of a pERK phosphatase. Here we describe the isolation of a high molecular weight ( approximately 440 kDa), cholesterol-regulated pERK phosphatase that dephosphorylates both the phosphotyrosine and the phosphothreonine residues in the activation loop of the enzyme. The dual activity in the complex appears to be due to the combined activities of the serine/threonine phosphatase PP2A and the tyrosine phosphatase HePTP. Acute depletion of cholesterol causes the disassembly of the complex and a concomitant loss of the dual specificity pERK phosphatase activity. The existence of a cholesterol-regulated HePTP/PP2A activity provides a molecular explanation for why ERK activity is sensitive to membrane cholesterol levels, and raises the possibility that ERK plays a role in regulating the traffic of cholesterol to caveolae/rafts and other membranes.

Biological Transport, Active↗

PubMed2003

The Sec1p/Munc18 (SM) protein, Vps45p, cycles on and off membranes during vesicle transport.

Protein phosphatase 1 (PP1, Glc7p) functions in the final stage of SNARE-mediated vesicle transport between docking and fusion. During this process, trans-SNARE complexes, formed between molecules in opposing membranes, convert to cis-complexes, with all participants in the same lipid bilayer. Here, we show that glc7 mutant cells accumulate SNARE complexes. These complexes are clearly different from those found in either wild-type or sec18-1 cells as the Sec1p/Munc18 (SM) protein Vps45p does not bind to them. Given that PP1 controls fusion, the SNARE complexes that accumulate in glc7 mutants likely represent trans-SNARE complexes. Vps45p dissociates from the membrane in the absence of PP1 activity, but rapidly reassociates after its reactivation. These data reveal that SM proteins cycle on and off membranes in a stage-specific manner during the vesicle transport reaction, and suggest that protein phosphorylation plays a key role in the regulation of this cycle.

Biological Transport, Active↗

PubMed2003

Differential terminal fucosylation of N-linked glycans versus protein O-fucosylation in leukocyte adhesion deficiency type II (CDG IIc).

LAD II/CDG IIc is a rare autosomal recessive disease characterized by a decreased expression of fucosylated antigens on cell surfaces that results in leukocyte adhesion deficiency and severe neurological and developmental abnormalities. Its molecular basis has been identified as a defect in the transporter of GDP-l-fucose into the Golgi lumen, which reduces the availability of the substrate for fucosyltransferases. During metabolic radiolabeling experiments using [3H]fucose, LAD II fibroblasts incorporated significantly less radiolabel compared with control cells. However, fractionation and analysis of the different classes of glycans indicated that the decrease in [3H]fucose incorporation is not generalized and is mainly confined to terminal fucosylation of N-linked oligosaccharides. In contrast, the total levels of protein O-fucosylation, including that observed in Notch protein, were unaffected. This finding demonstrates that the decrease in GDP-l-fucose levels in the fibroblast Golgi caused by the LAD II defect does not impair bulk protein O-fucosylation, but severely affects the bulk addition of fucose as a terminal modification of N-linked glycans. These data suggest that the severe clinical abnormalities including neurological and developmental ones observed in at least some of the LAD II patients may be related to alteration in recognition systems involving terminal fucose modifications of N-glycans and not be due to a defective O-fucosylation of proteins such as Notch.

Biological Transport, Active↗