No description available.

Session ID: SU-G2-4 / Joint 4th International Conference on Soft Computing and Intelligent Systems and 9th International Symposium on advanced Intelligent Systems, September 17-21, 2008, Nagoya University, Nagoya, Japan

Session ID: TH-B1-3 / SCIS & ISIS 2010, Joint 5th International Conference on Soft Computing and Intelligent Systems and 11th International Symposium on Advanced Intelligent Systems. December 8-12, 2010, Okayama Convention Center, Okayama, Japan

The purpose of this study was to examine how the number of cultural remains, the area of the final felling site and the forest owner’s knowledge, attitude and behavior related to the consideration taken to cultural environments. The study was built upon results from the HK-inventory as well as qualitative interviews with seven forest owners.   The results indicated that the risk of negative impact increased when two or more cultural remains were located at the felling site. Felling sites where two or more cultural remains had been affected and where at least one of these remains was affected negatively, were also larger than those sites where adequate consideration had been taken. Furthermore, the forest owner’s knowledge and attitude could have an effect on his or her behavior in regards to cultural consideration.   Larger felling sites that affect two or more cultural remains should be extra monitored before and during felling procedures to ensure adequate consideration towards cultural environments located at the site. Forest owners can probably have an influence on consideration but need more knowledge about different types of cultural environments and how to act to achieve adequate consideration towards cultural environments in general.

Session ID: TH-G3-5 / Joint 4th International Conference on Soft Computing and Intelligent Systems and 9th International Symposium on advanced Intelligent Systems, September 17-21, 2008, Nagoya University, Nagoya, Japan

No description available.

No description available.

Regulation of Glucose metabolism is known to play an important role in pathogenesis of many diseases. Primarily because deregulation of this metabolic pathway can lead to either apoptosis or extended life span of the cells involved. Viruses are parasitic in nature, they utilize the host cellular pathways to support their own progeny; hence it is expected that viruses would regulate the central glucose metabolism of infected host cells. Human immunodeficiency virus type 1 (HIV-1) causes acquired immune deficiency syndrome, and it uniquely infects both activated CD4+ T cells and terminally differentiated macrophages during the course of HIV-1 pathogenesis. While HIV-1 infection of CD4+ T cells induces G2 arrest and cell death within 2-3 days, HIV-1 infection of macrophages results in longer survival of infected cells and low constitutive viral production, generating viral reservoirs. Our studies show that HIV-1 infection lead to significant changes in the glycolytic pathway of infected cells by altering the enzymatic activity and protein expression of various glycolytic components. The data suggests that the two HIV-1 target cell types exhibit very different metabolic outcomes. During viral replication in monocyte/macrophage lineage cells we observe increase in glycolytic protein expression and the same proteins show no modulation in T-cell lines post viral replication. Similar differential regulation is observed in case of enzymatic activity of glycolytic enzymes as well. We also conducted proteomic studies in collaboration with the proteomics core. HIV-1 encoded viral protein Vpr is essential for infection of macrophages by HIV-1. Vpr is known to cause cell cycle block in infected cell and bring about cell death. However, macrophages are resistant to cell death and are viral reservoir, even Vpr over expression does not cause apoptosis in these cell types. The goal of the study was to use a stable-isotope labeling by amino acids in cell culture (SILAC) coupled with mass spectrometry-based proteomics approach to characterize the Vpr response in macrophages. More than 600 proteins were quantified in SILAC coupled with LC-MS/MS approach, among which 136 were significantly altered upon Vpr overexpression in macrophages. The proteomic data illustrating increase in abundance of enzymes in the glycolytic pathway (pentose phosphate and pyruvate metabolism) was further validated by western blot analysis. We observed that HIV-1 hijacks the macrophage glucose metabolism pathway via the Vpr-hypoxia inducible factor 1 alpha (HIF-1 alpha) axis to induce expression of hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD) and pyruvate kinase muscle type 2 (PKM2) that facilitates viral replication and biogenesis, and long-term survival of macrophages. We then focused on infected monocyte macrophages to identify if glycolytic components such as HK and G6PD were regulated by HIV-1 infection/replication. We report that Hexokinase-1 (HK-1) enzyme expression increases post infection of PBMCs where as the enzymatic activity of HK decreases. Similar effect is seen with HIV-1 replication in latently infected monocyte cell lines U1. The G6PD enzyme activity and expression both increases in infected PBMCs and in U1 cells post induction of viral replication with PMA. We also found that HK-1 translocate to the mitochondria of U1 cells post induction of HIV-1. It is known that the product of HK activity, Glucose 6-phosphate (G6P) releases HKI from the outer leaflet of mitochondria. Hence we conclude that the viral infection decreases HK activity to have less G6P produced in cell and increases G6PD enzyme activity ensuring the remaining G6P is quickly used up, supporting the adherence of outer mitochondrial membrane bound HK1. This sequence of cellular events ensures longer survival of infected cells supporting the viral progeny to propagate in the cell. We further show that suppressing the Pentose phosphate pathway (PPP) by blocking G6PD activity is not only detrimental to the survival of the infected cells it also suppresses viral replication and promoter level transactivation of the viral LTR. Next we sought to identify if glycolytic enzyme PKM2, that is also known to play a nonmetabolic dual role as a protein kinase regulating gene transcription has any effect on the transcription of HIV-LTR. Our study demonstrates upregulation of pyruvate kinase isoform M2 (PKM2) expression in whole cell extracts and nuclear extracts of HIV-1JRFL infected PBMCs and during reactivation of HIV-1 in chronically infected U1 cells. We then focused on understanding the potential role of PKM2 on HIV-1 LTR transactivation. Our studies demonstrate that over expression of PKM2 leads to transactivation of the HIV-1 LTR reporter construct. Using various deletions constructs of HIV-1 LTR, we mapped the region spanning between -120 bp to -80 bp to be essential for PKM2 mediated transactivation. This region contains the NFKB DNA binding site and mutation of NFKB binding site attenuated PKM2 mediated transactivation of HIV-LTR. Chromatin immune-precipitation (ChIP) analysis confirmed interaction of PKM2 with HIV-1 LTR. Our studies suggest that PKM2 is a transcriptional co-activator of HIV-1 LTR. Hence it opens up another possible target to curb HIV-1 replication at transcriptional level. This study sheds light on the regulation of glycolytic pathway of host cells by HIV-1 infection and its consequences for the virus, opening up new avenues to target viral replication and identify glycolytic markers of HIV-1 pathogenesis. / Biology

Thesis (M.B.A.)--University of Hong Kong, 1996. / Includes bibliographical references.

Pseudomonas aeruginosa (Pa) est une bactérie multi-résistante responsable de plus de 10% des infections nosocomiales en Europe. Pa réagit aux signaux environnementaux en activant un système de régulation complexe qui permet à la bactérie d’adopter une mode de vie planctonique (infection aigue) ou sessile (infection chronique caractérisée par la formation des biofilms). Le système à deux composants GacS/GacA joue un rôle central dans la permutation entre ces deux modes. Pendant une infection chronique, GacS HK forme des homodimeres permettant l’activation de la formation du biofilm. Nos travaux ont confirmé le rôle du domaine périplasmique de GacS HK (GacSp) dans la détection du signal et l’activation de la voie GacS/GacA. Malgré l’instabilité de GacSp, J’ai résolu la structure 3D de ce domaine par la spectroscopie RMN. GacSp adopte un repliement PDC qui caractérise un grand nombre de domaines senseurs connus pour fixer une large gamme de ligands. L’étude de la structure m’a permis de proposer un site de fixation du ligand. Les résultats présentés dans cette thèse montrent l’importance de GacSp et propose une nouvelle piste pour les études thérapeutiques visant à éradiquer le biofilm.La deuxième partie de ma thèse présente la structure cristalline du glycoside hydrolase 39 du B. cellulosilyticus WH2 présente dans le côlon (GH39wh2). GH39wh2 partage la même architecture avec les autres membres de la famille 39, cependant, elle possède un site actif plus large et plus exposé. Les analyses structurales et bioinformatiques ont permis d’attribuer GH39wh2 à un nouveau sous-groupe caractérisé par une fonction endoglycosidase inconnue. / Pseudomonas aeruginosa (Pa) is a Multidrug-Resistant bacterium responsible for more than 10% of nosocomial infections in Europe. Interestingly, Pa can switch its lifestyle between planktonic (acute infection) and sessile lifestyle (biofilm-type chronic infection) through different regulatory pathways, in which GacS/GacA Two Component System (TCS) plays a central decisive role. An active homodimer form of GacS Histidine Kinase (HK) leads to biofilm formation, while the inhibition of GacS by the hybrid HK RetS via cytoplasmic hetero-dimerization promotes acute infection. During my thesis, we unveiled for the first time the sensing role of the periplasmic detection domain of GacS HK (GacSp). I further solved the 3D structure of GacSp using NMR spectroscopy revealing its PDC-like fold, which characterizes a large number of detection domains known to bind a wide range of ligands. The structural analyses of the new GacSp structure suggest a conserved ligand-binding pocket. All together, my results present structural and functional understanding of GacSp role, which form the basis to consider this domain as a new target for anti-biofilm therapy.In the second part of my thesis, I report a 2.5Å resolution crystal structure of a family 39 glycoside hydrolase member (GH39wh2) from the human gut bacteria B. cellulosilyticus WH2. GH39wh2 shares a similar architecture as found in other related GH39 members but unveils an atypical shallow solvent-exposed groove. Complementary biochemical and bioinformatics analyses assign GH39wh2 to a new GH39 subgroup harboring a yet unknown endoglycosidase activity.