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Full-Text Articles in Medicine and Health Sciences

Interpreting Hemoglobin And Water Concentration, Oxygen Saturation, And Scattering Measured In Vivo By Near-Infrared Breast Tomography, Subhadra Srinivasan, Brian W. Pogue, Shudong Jiang, Hamid Dehghani, Christine Kogel, Sandra Soho, Jennifer J. Gibson, Tor D. Tosteson, Steven P. Poplack, Keith D. Paulsen Oct 2003

Interpreting Hemoglobin And Water Concentration, Oxygen Saturation, And Scattering Measured In Vivo By Near-Infrared Breast Tomography, Subhadra Srinivasan, Brian W. Pogue, Shudong Jiang, Hamid Dehghani, Christine Kogel, Sandra Soho, Jennifer J. Gibson, Tor D. Tosteson, Steven P. Poplack, Keith D. Paulsen

Dartmouth Scholarship

Near-infrared spectroscopic tomography was used to measure the properties of 24 mammographically normal breasts to quantify whole-breast absorption and scattering spectra and to evaluate which tissue composition characteristics can be determined from these spectra. The absorption spectrum of breast tissue allows quantification of (i) total hemoglobin concentration, (ii) hemoglobin oxygen saturation, and (iii) water concentration, whereas the scattering spectrum provides information about the size and number density of cellular components and structural matrix elements. These property data were tested for correlation to demographic information, including subject age, body mass index, breast size, and radiographic …


Regulation And Localization Of Endogenous Human Tristetraprolin, Anna-Marie Fairhurst, John E. Connolly, Katharine A Hintz, Nicolas J Goulding May 2003

Regulation And Localization Of Endogenous Human Tristetraprolin, Anna-Marie Fairhurst, John E. Connolly, Katharine A Hintz, Nicolas J Goulding

Dartmouth Scholarship

Tumor necrosis factor (TNF) has been implicated in the development and pathogenicity of infectious diseases and autoimmune disorders, such as septic shock and arthritis. The zinc-finger protein tristetraprolin (TTP) has been identified as a major regulator of TNF biosynthesis. To define its intracellular location and examine its regulation of TNF, a quantitive intracellular staining assay specific for TTP was developed. We establish for the first time that in peripheral blood leukocytes, express


Rhythmic Binding Of A White Collar-Containing Complex To The Frequency Promoter Is Inhibited By Frequency, Allan C. Froehlich, Jennifer J. Loros, Jay C. Dunlap May 2003

Rhythmic Binding Of A White Collar-Containing Complex To The Frequency Promoter Is Inhibited By Frequency, Allan C. Froehlich, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

The biological clock of Neurospora crassa includes interconnected transcriptional and translational feedback loops that cause both the transcript and protein encoded by the frequency gene (frq) to undergo the robust daily oscillations in abundance, which are essential for clock function. To understand better the mechanism generating rhythmic frq transcript, reporter constructs were used to show that the oscillation in frq message is transcriptionally regulated, and a single cis-acting element in the frq promoter, the Clock Box (C box), is both necessary and sufficient for this rhythmic transcription. Nuclear protein extracts used in binding assays revealed that a White Collar (WC)-1- …


Alpha-Toxin Is Required For Biofilm Formation By Staphylococcus Aureus, Nicky C. Caiazza, George A. O'Toole May 2003

Alpha-Toxin Is Required For Biofilm Formation By Staphylococcus Aureus, Nicky C. Caiazza, George A. O'Toole

Dartmouth Scholarship

Staphylococcus aureus is a common pathogen associated with nosocomial infections. It can persist in clinical settings and gain increased resistance to antimicrobial agents through biofilm formation. We have found that alpha-toxin, a secreted, multimeric, hemolytic toxin encoded by the hla gene, plays an integral role in biofilm formation. The hla mutant was unable to fully colonize plastic surfaces under both static and flow conditions. Based on microscopy studies, we propose that alpha-hemolysin is required for cell-to-cell interactions during biofilm formation.


Rhamnolipid Surfactant Production Affects Biofilm Architecture In Pseudomonas Aeruginosa Pao1, Mary E. Davey, Nicky C. Caiazza, George A. O'Toole Feb 2003

Rhamnolipid Surfactant Production Affects Biofilm Architecture In Pseudomonas Aeruginosa Pao1, Mary E. Davey, Nicky C. Caiazza, George A. O'Toole

Dartmouth Scholarship

In response to certain environmental signals, bacteria will differentiate from an independent free-living mode of growth and take up an interdependent surface-attached existence. These surface-attached microbial communities are known as biofilms. In flowing systems where nutrients are available, biofilms can develop into elaborate three-dimensional structures. The development of biofilm architecture, particularly the spatial arrangement of colonies within the matrix and the open areas surrounding the colonies, is thought to be fundamental to the function of these complex communities. Here we report a new role for rhamnolipid surfactants produced by the opportunistic pathogen Pseudomonas aeruginosa in the maintenance of biofilm architecture. …


A Genetic Lesion That Arrests Plasma Cell Homing To The Bone Marrow, Loren D. Erickson, Ling-Li Lin, Biyan Duan, Laurence Morel, Randolph J. Noelle Jan 2003

A Genetic Lesion That Arrests Plasma Cell Homing To The Bone Marrow, Loren D. Erickson, Ling-Li Lin, Biyan Duan, Laurence Morel, Randolph J. Noelle

Dartmouth Scholarship

The coordinated regulation of chemokine responsiveness plays a critical role in the development of humoral immunity. After antigen challenge and B cell activation, the emerging plasma cells (PCs) undergo CXCL12-induced chemotaxis to the bone marrow, where they produce Ab and persist. Here we show that PCs, but not B cells or T cells from lupus-prone NZM mice, are deficient in CXCL12-induced migration. PC unresponsiveness to CXCL12 results in a marked accumulation of PCs in the spleen of mice, and a concordant decrease in bone marrow PCs. Unlike normal mice, in NZM mice, a majority of the splenic PCs are long-lived. …