Medical Microbiology Commons^™

Assembly And Development Of The Pseudomonas Aeruginosa Biofilm Matrix., Luyan Ma, Matthew Conover, Haiping Lu, Matthew R. Parsek, Kenneth W. Bayles, Daniel J. Wozniak

Journal Articles: Pathology and Microbiology

Virtually all cells living in multicellular structures such as tissues and organs are encased in an extracellular matrix. One of the most important features of a biofilm is the extracellular polymeric substance that functions as a matrix, holding bacterial cells together. Yet very little is known about how the matrix forms or how matrix components encase bacteria during biofilm development. Pseudomonas aeruginosa forms environmentally and clinically relevant biofilms and is a paradigm organism for the study of biofilms. The extracellular polymeric substance of P. aeruginosa biofilms is an ill-defined mix of polysaccharides, nucleic acids, and proteins. Here, we directly visualize …

Apd2: The Updated Antimicrobial Peptide Database And Its Application In Peptide Design., Guangshun Wang, Xia Li, Zhe Wang

Journal Articles: Pathology and Microbiology

The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/main.php) has been updated and expanded. It now hosts 1228 entries with 65 anticancer, 76 antiviral (53 anti-HIV), 327 antifungal and 944 antibacterial peptides. The second version of our database (APD2) allows users to search peptide families (e.g. bacteriocins, cyclotides, or defensins), peptide sources (e.g. fish, frogs or chicken), post-translationally modified peptides (e.g. amidation, oxidation, lipidation, glycosylation or d-amino acids), and peptide binding targets (e.g. membranes, proteins, DNA/RNA, LPS or sugars). Statistical analyses reveal that the frequently used amino acid residues (>10%) are Ala and Gly in bacterial peptides, Cys and Gly in plant …

Epithelial Cell Gene Expression Induced By Intracellular Staphylococcus Aureus., Xianglu Li, William G. Fusco, Keun S. Seo, Kenneth W. Bayles, Erin E. Mosley, Mark A. Mcguire, Gregory A. Bohach

Journal Articles: Pathology and Microbiology

HEp-2 cell monolayers were cocultured with intracellular Staphylococcus aureus, and changes in gene expression were profiled using DNA microarrays. Intracellular S. aureus affected genes involved in cellular stress responses, signal transduction, inflammation, apoptosis, fibrosis, and cholesterol biosynthesis. Transcription of stress response and signal transduction-related genes including atf3, sgk, map2k1, map2k3, arhb, and arhe was increased. In addition, elevated transcription of proinflammatory genes was observed for tnfa, il1b, il6, il8, cxcl1, ccl20, cox2, and pai1. Genes involved in proapoptosis and fibrosis were also affected at transcriptional level by intracellular S. aureus. Notably, intracellular S. aureus induced strong transcriptional down-regulation of several …

Stromal Gene Signatures In Large-B-Cell Lymphomas., G Lenz, G Wright, S S Dave, W Xiao, J Powell, H Zhao, W Xu, B Tan, N Goldschmidt, Javeed Iqbal, Julie M. Vose, M Bast, Kai Fu, D D. Weisenburger, T C Greiner, James O. Armitage, A Kyle, L May, R D Gascoyne, J M Connors, G Troen, H Holte, S Kvaloy, D Dierickx, G Verhoef, J Delabie, E B Smeland, P Jares, A Martinez, A Lopez-Guillermo, E Montserrat, E Campo, R M Braziel, T P Miller, L M Rimsza, J R Cook, B Pohlman, J Sweetenham, R R Tubbs, R I Fisher, E Hartmann, A Rosenwald, G Ott, H-K Muller-Hermelink, D Wrench, T A Lister, E S Jaffe, W H Wilson, W C. Chan, L M Staudt

Journal Articles: Pathology and Microbiology

BACKGROUND: The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear.

METHODS: We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group.

RESULTS: A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted …

Microglia And Astrocyte Activation By Toll-Like Receptor Ligands: Modulation By Ppar-Gamma Agonists., Catherine Gurley, Jessica Nichols, Shuliang Liu, Nirmal K. Phulwani, Nilufer Esen, Tammy Kielian

Journal Articles: Pathology and Microbiology

Microglia and astrocytes express numerous members of the Toll-like receptor (TLR) family that are pivotal for recognizing conserved microbial motifs expressed by a wide array of pathogens. Despite the critical role for TLRs in pathogen recognition, when dysregulated these pathways can also exacerbate CNS tissue destruction. Therefore, a critical balance must be achieved to elicit sufficient immunity to combat CNS infectious insults and downregulate these responses to avoid pathological tissue damage. We performed a comprehensive survey on the efficacy of various PPAR-gamma agonists to modulate proinflammatory mediator release from primary microglia and astrocytes in response to numerous TLR ligands relevant …

Clinical Implication Of Genome-Wide Profiling In Diffuse Large B-Cell Lymphoma And Other Subtypes Of B-Cell Lymphoma., Javeed Iqbal, Shantaram Joshi, Kavita N. Patel, Sofi I. Javed, Can Kucuk, Afeera Aabida, Francesco D'Amore, Kai Fu

Journal Articles: Pathology and Microbiology

The differentiation of lymphoid cells is tightly regulated by transcription factors at various stages during their development. During the maturation processes, different genomic alterations or aberrations such as chromosomal translocation, mutation and deletions may occur that can eventually result in distinct biological and clinical tumors. The different differentiation stages create heterogeneity in lymphoid malignancies, which can complicate the diagnosis. The initial diagnostic scheme for lymphoid diseases was coined by Rappaport followed by Revised European and American Classification of Lymphoid Neoplasms (REAL) and World Health Organization (WHO) classifications. These classification methods were based on histological, immunophenotypic and cytogenetic markers and widely …

Effects Of Low Dose Gm-Csf On Microglial Inflammatory Profiles To Diverse Pathogen-Associated Molecular Patterns (Pamps)., Nilufer Esen, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: It is well appreciated that obtaining sufficient numbers of primary microglia for in vitro experiments has always been a challenge for scientists studying the biological properties of these cells. Supplementing culture medium with granulocyte-macrophage colony-stimulating factor (GM-CSF) partially alleviates this problem by increasing microglial yield. However, GM-CSF has also been reported to transition microglia into a dendritic cell (DC)-like phenotype and consequently, affect their immune properties.

METHODS: Although the concentration of GM-CSF used in our protocol for mouse microglial expansion (0.5 ng/ml) is at least 10-fold less compared to doses reported to affect microglial maturation and function (>/= …

Molecular Diagnosis Of Burkitt's Lymphoma., Sandeep S. Dave, Kai Fu, George W. Wright, Lloyd T. Lam, Philip Kluin, Evert-Jan Boerma, Timothy Greiner, Dennis D. Weisenburger, Andreas Rosenwald, German Ott, Hans-Konrad Müller-Hermelink, Randy D. Gascoyne, Jan Delabie, Lisa M. Rimsza, Rita M. Braziel, Thomas M. Grogan, Elias Campo, Elaine S. Jaffe, Bhavana J. Dave, Warren Sanger, M Bast, Julie M. Vose, James O. Armitage, Joseph M. Connors, Erlend B. Smeland, Stein Kvaloy, Harald Holte, Richard I. Fisher, Thomas P. Miller, Emilio Montserrat, Wyndham H. Wilson, Manisha Bahl, Hong Zhao, Liming Yang, John Powell, Richard Simon, Wing C. Chan, Louis M. Staudt

Journal Articles: Pathology and Microbiology

BACKGROUND: The distinction between Burkitt's lymphoma and diffuse large-B-cell lymphoma is crucial because these two types of lymphoma require different treatments. We examined whether gene-expression profiling could reliably distinguish Burkitt's lymphoma from diffuse large-B-cell lymphoma.

METHODS: Tumor-biopsy specimens from 303 patients with aggressive lymphomas were profiled for gene expression and were also classified according to morphology, immunohistochemistry, and detection of the t(8;14) c-myc translocation.

RESULTS: A classifier based on gene expression correctly identified all 25 pathologically verified cases of classic Burkitt's lymphoma. Burkitt's lymphoma was readily distinguished from diffuse large-B-cell lymphoma by the high level of expression of c-myc target …

Immunopathogenesis Of Brain Abscess., Tammy Kielian

Journal Articles: Pathology and Microbiology

Brain abscess represents a significant medical problem despite recent advances made in detection and therapy. Due to the emergence of multi-drug resistant strains and the ubiquitous nature of bacteria, the occurrence of brain abscess is likely to persist. Our laboratory has developed a mouse experimental brain abscess model allowing for the identification of key mediators in the CNS anti-bacterial immune response through the use of cytokine and chemokine knockout mice. Studies of primary microglia and astrocytes from neonatal mice have revealed that S. aureus, one of the main etiologic agents of brain abscess in humans, is a potent stimulus for …

Analysis Of The Effects Of Overexpression Of Metallothionein-I In Transgenic Mice On The Reproductive Toxicology Of Cadmium., T Dalton, Kai Fu, G C Enders, R D Palmiter, G K Andrews

Journal Articles: Pathology and Microbiology

Exposure to low levels of cadmium reduces fertility. In male mice spermatogenesis is highly sensitive to cadmium, whereas in females the peri-implantation period of pregnancy is sensitive. To examine the potential roles of the cadmium-binding protein, metallothionein (MT), in the reproductive toxicology of cadmium, we examined a transgenic mouse strain that overexpresses metallothionein-I (MT-I). These mice had dramatically increased steady-state levels of MT-I mRNA and MT in the testes and in the female reproductive tract during the peri-implantation period of pregnancy, and this overexpression occurred in a cell-specific and temporally regulated manner similar to that of the endogenous MT-I gene. …