Inflammation can be up-regulated by microglia and macrophages through the release of pro-inflammatory cytokines such as tumour necrosis factor-alpha (TNF-α). Excess production of TNF-α can lead to a variety of diseases and even tissue necrosis. Recently, the expression of alpha seven acetylcholine receptors (α7AChR) by microglia have been shown to decrease the amount of TNF-α released. This anti-inflammatory pathway has been studied extensively where researchers are able to reduce TNF-α concentration through α7AChR expression and increases in the concentration of its ligand. I have shown that Neuregulin is able to increase the expression of α7AChR in microglia and macrophages. Using three immortalized cell lines, BV-2, EOC-20 and RAW 264.7, and primary microglial cells harvest from mice I investigated the role that neuregulin plays in the anti-inflammatory process. Neuregulin signals through the ErbB receptors, a family of tyrosine kinase receptors, to facilitate the effects on ACh expression. My results show that ErbB4 is expressed in BV-2, EOC-20 and RAW 264.7 cell lines while ErbB2-4 receptors are expressed in primary microglia. As well, I was able to show that ErbB4 became phosphorylated upon binding to NRG in immortalized cell lines. Using an Enzyme Linked Immunsorbent Assay to analyze TNF- α concentration in microglia and macrophages, I was able to demonstrate that increased levels of α7AChRs did not result in a reduction in TNF-α concentration. These results showed that NRG is able to increase α7AChRs in microglia and macrophages after the phosphorylation of the ErbB4 receptors. As well, this increase in α7AChR does not relate to a reduction in TNF-α, thus under these experimental conditions does not have an effect on the anti-inflammatory pathway.

Inflammation can be up-regulated by microglia and macrophages through the release of pro-inflammatory cytokines such as tumour necrosis factor-alpha (TNF-α). Excess production of TNF-α can lead to a variety of diseases and even tissue necrosis. Recently, the expression of alpha seven acetylcholine receptors (α7AChR) by microglia have been shown to decrease the amount of TNF-α released. This anti-inflammatory pathway has been studied extensively where researchers are able to reduce TNF-α concentration through α7AChR expression and increases in the concentration of its ligand. I have shown that Neuregulin is able to increase the expression of α7AChR in microglia and macrophages. Using three immortalized cell lines, BV-2, EOC-20 and RAW 264.7, and primary microglial cells harvest from mice I investigated the role that neuregulin plays in the anti-inflammatory process. Neuregulin signals through the ErbB receptors, a family of tyrosine kinase receptors, to facilitate the effects on ACh expression. My results show that ErbB4 is expressed in BV-2, EOC-20 and RAW 264.7 cell lines while ErbB2-4 receptors are expressed in primary microglia. As well, I was able to show that ErbB4 became phosphorylated upon binding to NRG in immortalized cell lines. Using an Enzyme Linked Immunsorbent Assay to analyze TNF- α concentration in microglia and macrophages, I was able to demonstrate that increased levels of α7AChRs did not result in a reduction in TNF-α concentration. These results showed that NRG is able to increase α7AChRs in microglia and macrophages after the phosphorylation of the ErbB4 receptors. As well, this increase in α7AChR does not relate to a reduction in TNF-α, thus under these experimental conditions does not have an effect on the anti-inflammatory pathway.

The fundamental principles governing the natural phenomena of life is one of the critical issues receiving due importance in recent years. Most complex real-world systems are found to have a similar networking model that manages their behavioral pattern. Recent scientific discoveries have furnished evidence that most real world networks follow a scale-free architecture. A number of research efforts are in progress to facilitate the learning of valuable information by recognizing the underlying reality in the vast amount of genomic data that is becoming available. A key feature of scale-free architecture is the vitality of the highly connected nodes (hubs). This project focuses on the multi-cellular organism <i>Drosophila melanogaster</i>, an established model system for human biology. The major objective is to analyze the protein-protein interaction and the metabolic network of the organism to consider the architectural patterns and the consequence of removal of hubs on the topological parameters of the two interaction networks. <p> Analysis shows that both interaction networks pursue a scale-free model establishing the fact that real networks from varied situations conform to the small world pattern. Similarly, the topology of the two networks suffers drastic variations on the removal of the hubs. It is found that the topological parameters of average path length and diameter show a two-fold and three-fold increase on the deletion of hubs for the protein-protein interaction and metabolic interaction network, respectively. The arbitrary exclusion of the nodes does not show any remarkable disparity in the topological parameters of the two networks. This aberrant behavior for the two cases underscores the significance of the most linked nodes to the natural topology of the networks.

The global gene expression profiles of industrial strains of <i>Saccharomyces cerevisiae</i> responding to nitrogen deficiency and very high sugar concentrations stresses were determined by oligonucleotide microarray analysis of ~ 6200 yeast open reading frames. Genomics analysis showed that 400 genes in S. cerevisiae was differentially expressed by more than 1.5-fold compared with controls at late-logarithmic phase of fermentation, as the yeast adapted to changing nutritional, environmental and physiological conditions. The genes of many pathways are regulated in a highly coordinated manner. The repressed expression of GDH1 and up-regulation of ARO10 within the contrast of Q270/Q10 indicated high energy demanding of yeast cells under high sugar stress. Activities of G3P shuttle indicated that under very high gravity environment, sufficient assimilatory nitrogen enhances yeasts ability of redox balancing, and therefore higher stress-tolerance and higher fermentation efficiency of yeast. Under contrast W270/Q270, the up-regulation of DUR1,2 responsible for urea degradation induces the glutamate biosynthesis and the consumption of -ketoglutarate. This may indicate that higher nitrogen level would enable higher activities in the TCA cycle, and therefore generate more energy for biosynthesis and yeast cell proliferation under very high gravity fermentation conditions. Nitrogen metabolism was also stimulated by high nitrogen level when yeast was grown in very high gravity environment.

The secretory pathway of plant cells consists of several organelles that are connected by vesicle and tubular transport. Every compartment has a distinct function and the specificity of vesicle fusion is essential to maintain the organelles identity. N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) play a crucial role in the secretory pathway driving specific vesicle fusions. A vesicle SNARE (v-SNARE) on a vesicle specifically interacts with two or three target SNAREs (t-SNAREs) on the target compartment. This event leads to vesicle membrane fusion with the membrane of the target compartment and the release of cargo molecules into the organelle lumen.<p> The aim of this work was the characterization of two <i>Arabidopsis thaliana</i> SNAREs. The first one is a v-SNARE, Bet11 that is the Arabidopsis ortholog of the yeast and mammal ER-Golgi v-SNARE, Bet1. In these organisms, Bet1 is involved in trafficking between the ER and Golgi apparatus. The second protein studied is a putative SNARE called Bet12 that shares high sequence identity with Bet11. In particular, I was interested in studying the sorting of these two proteins and their role in the secretory pathway of plant cells. By confocal laser microscopy, I demonstrated that these two proteins have different intracellular localization: Bet11 was mainly localized on the ER, Golgi stacks and punctate structures that I have identified as endosomes. Bet12 was localized only on the Golgi stacks. The identification of signal(s) involved in targeting of Bet11 and Bet12 were studied. To reach this aim I generated different mutant chimeras of Bet11 and Bet12. The co-expression of these chimeras with specific protein markers suggested that the distribution of these proteins was the result of a combined influence of multiple domains.<p> A serine in the Bet11 sequence was identified as a putative phosphorylation site and appeared important for proper Bet11 intracellular distribution.<p> The different intracellular distributions of Bet11 and Bet12 suggest different biological roles for the two proteins. To functionally characterize these two proteins homozygous knock-down mutants of Bet11 were screened. These plants had no evident phenotype, suggesting a possible genetic redundancy in this SNARE family.

STK11/LKB1, a serine/threonine protein kinase, is a key upstream kinase of adenine monophosphate-activated protein kinase (AMPK), a necessary kinase in the control of metabolism for maintaining energy homeostasis. Although it has become clear that LKB1 is mutated in a significant number of Peutz¡VJeghers syndrome (PJS) and sporadic cancers, most frequently in adenocarcinoma of the lung, little is known about how the LKB1 signaling regulates the metabolic process and energy production underlying hypoxia and increased radiosensitivity of lung tumor. Here, we employed lung cancer cells as a model system to dissect the functional roles of LKB1 signaling in human lung adenocarcinoma. We found that LKB1 inhibits lung cancer cell migration, transformation and chemo-resistance in vitro after we restored LKB1 expression in LKB1 null A549 and H460 lung cancer cells. We also found that LKB1 prevents UV-induced DNA damage in human lung cancer cell lines by comet assay and activated UV-induced apopotsis by MTT assays. Furthermore, we designed a systems biology approach to provide a comprehensive protein-protein interaction analysis in order to elucidate the LKB1 tumor suppressor network in vivo. We employed Immunoprecipitation-HPLC- Mass Spectrometry (IP-LC-MS) to identify the novel proteins interacting with LKB1 under different cellular stress conditions. We have identified that LKB1 is involved in CFTR synthesis pathway underlying normoxia condition and participates in the glycolysis and gluconeogenesis pathways underlying hypoxia condition. Together, our findings indicated that LKB1 is involved in the regulation of cell migration, energy metabolism and DNA repair in lung cancer cells, and should provides insights to further exploit the concept of deranged cancer bioenergetics and aberrant growth signals to achieve more effective and selective strategies for lung cancer patients.

The exponential growth of information demands the automated movement of data and software via new software models that are able to integrate data and components on their own without scientists’ direct involvement. However, current stand-alone software modeling environments do not support a secure software execution, nor do client server applications allow user customization of the software running on the servers. To address this problem, a biological pathway modeling environment was built as a stand-alone Rich Internet Application (RIA). The modeling environment was tested by constructing a simulation of the glycolysis pathways in the human erythrocytes, and the results were compared against one of the latest and richest erythrocyte metabolism models developed by Kuchel and Mulquiney. The working simulation was able to settle into a quasi-stable state, with substrate concentrations close to what Kuchel and Mulquiney presented. It was also found that while the browser environment does allow for dynamic applications to be developed, speed and performance do become major issues. In later versions, it is hoped that the performance of the simulator can be increased and that it will become possible to link models together and add collaboration tools.

Blood is a complex mixture of formed cellular elements, proteins, and ions dissolved in a solution. It is a difficult fluid to model because it is a shear-thinning, viscoelastic fluid that stress- relaxes. In this study, a new mathematical model for whole blood is developed from a general equation for a fluid with a shear dependent viscosity. The model is then used as a backdrop for 28 different biochemical factors interacting to form a clot. The full intrinsic and extrinsic pathways are both used in the simulation; the inclusion of the full intrinsic pathway is something that had not been done prior to this work. The model is executed in one spatial direction in an infinite domain as well as within a rigid walled cylinder using a finite volume scheme. The rigid wall, similar to the new mathematical equation for blood, is an oversimplification of actual in-vitro conditions. The results of both simulations show the formation and dissolution of the clot. Sensitivity analysis is then performed in the finite domain model by adjusting the initial levels of factors Va and Xa. The results show that by increasing the initial level of one or both of these factors leads to the quicker formation of a clot.

Abstract Since Mar. 1995, the National Health Insurance begin in Taiwan, the payment of health insurance gradually increase each year. For controlling the increasing costs, case payment was the most important method. For each hospital, using clinical pathway to control costs of case payment was an effective tool. But, there were still less literatures to discuss the efficiency of clinical pathway in Taiwan. We used a retrospective study design, to examine the length of stay, total costs and quality including the complications, morbidity and readmissions for total knee replacement surgery. The data before clinical pathway was from June 2001 to May 2002, total 219 cases. After clinical pathway, the data was from Jan. 2003 to Dec. 2003, total 207 cases. The results showed decrease length of stay from 7.4 to 6.6 days (10.8%), decrease total cost from 125,324 NTS to 119,100 NTS (4.97%) and the quality of complications and readmissions did not increase. In conclusion, the clinical pathway can improve length of stay, total costs and quality. Key words: case payment, clinical pathway, total knee replacement

The rise of medical expenses is a common problem in the whole- wide world. All those countries implementing National Health Insurance have been anxiously looking for solutions, and clinical pathway has been found to be the most effective tool to control the growth of medical expense and maintain the quality of healthcare. This study focuses on the development and implementation of clinical pathway of breast cancer who underwent modified radical mastectomy, and investigate the impact of implementation of clinical pathway on the control of the length of stay, inpatient medical care expenditures, healthcare quality, and patient¡¦s medical satisfaction. The 90 patients of MRM before implementation ( July 1999 to Sep. 2000 ) and 80 patients after implementation ( Jan. 2001 to Feb. 2002 ) are taken as the targets of this study. The major findings of the study are listed as follows: 1. Clinical pathway can reasonably control the length of stay. 2. Clinical pathway can reduce inpatient medical care expenditures. 3. Clinical pathway can improve healthcare quality. 4. Clinical pathway can improve patient¡¦s medical satisfaction. 5. Clinical pathway can influence doctor¡¦s partial practice pattern. Finally this study concludes that clinical pathway is an instructive tool for hospital management. Based on the results and discussion from the study, we suggest the implementation of clinical pathway cones best in conjunction with the impact of case payment; besides, the quality of medical care should be assured under the controlled medical cost.