Dynamics of genome change among Legionella species.

Legionella species inhabit freshwater and soil ecosystems where they parasitize protozoa. L. pneumonphila (LP) serogroup-1 (Lp1) is the major cause of Legionnaires' Disease (LD), a life-threatening pulmonary infection that can spread systemically.

Lateral flow-based antibody testing for Chlamydia trachomatis.

We describe here a lateral flow-based assay (LFA) for the detection of antibodies against immunodominant antigen Pgp3 from Chlamydia trachomatis, the causative agent of urogenital chlamydia infection and ocular trachoma. Optimal signal detection was achieved when the gold-conjugate and test line contained Pgp3, creating a dual sandwich capture assay. The LFA yielded positive signals with serum and whole blood but not with eluted dried blood spots.

Positive and negative affect and arousal: cross-sectional and longitudinal associations with adolescent cortisol diurnal rhythms.

Objectives: Psychobiological research with adolescent populations tends to focus on negative mood, stress, and psychopathology, but the role of positive emotions is insufficiently understood. The current study examines the relative contributions of both negative and positive affective experiences to the basal activity of the hypothalamic-pituitary-adrenal axis, measured by levels of cortisol across the waking day.

Methods: A sample of 315 ethnically and racially diverse high school students (mean age = 17.

Quantitative characterization of subject motion in HR-pQCT images of the distal radius and tibia.

Image quality degradation due to subject motion is a common artifact affecting in vivo high-resolution peripheral quantitative computed tomography (HR-pQCT) of bones. These artifacts confound the accuracy and reproducibility of bone density, geometry, and cortical and trabecular structure measurements. Observer-based systems for grading image quality and criteria for deciding when to repeat an acquisition and post hoc data quality control remain highly subjective and non-standardized.

Convection and retro-convection enhanced delivery: some theoretical considerations related to drug targeting.

Delivery of drugs and macromolecules into the brain is a challenging problem, due in part to the blood-brain barrier. In this article, we focus on the possibilities and limitations of two infusion techniques devised to bypass the blood-brain barrier: convection enhanced delivery (CED) and retro-convection enhanced delivery (R-CED). CED infuses fluid directly into the interstitial space of brain or tumor, whereas R-CED removes fluid from the interstitial space, which results in the transfer of drugs from the vascular compartment into the brain or tumor.

Coupled Nanomechanical and Raman Microspectroscopic Investigation of Human Third Molar DEJ.

The dentino-enamel junction (DEJ) connects enamel, that covers the outer surface of a tooth, to a thicker underlying dentin. The DEJ is a critical interface that permits joining these materials that have widely dissimilar mechanical properties. AFM-based nanoindentation and Raman microspectroscopy were used to define the width and composition of human molar DEJ.

Influence of multivalent nitrilotriacetic acid lipid-ligand affinity on the circulation half-life in mice of a liposome-attached His6-protein.

Metal chelation-ligand interactions, such as occur between nitrilotriacetic acid (NTA)-nickel and multihistidines, enable the noncovalent attachment of histidine-modified proteins to liposomes and other particles. We compared three lipids: a mono-NTA lipid (ca. 10 microM affinity) and two tris-NTA lipid derivatives (ca.

Resolution dependence of the non-metric trabecular structure indices.

Non-metric indices of topological features of trabecular bone structure, such as structure model index (SMI), connectivity density (Conn.D), and degree of anisotropy (DA), provide unique information relevant to bone quality. With recent technological advancement, in vivo assessment of these indices may be possible from images acquired using high-resolution imaging techniques such as high-resolution peripheral quantitative computed tomography (HR-pQCT).

Barriers to carrier mediated drug and gene delivery to brain tumors.

Brain tumor patients face a poor prognosis despite significant advances in tumor imaging, neurosurgery and radiation therapy. Potent chemotherapeutic drugs fail when used to treat brain tumors because biochemical and physiological barriers limit drug delivery into the brain. In the past decade a number of strategies have been introduced to increase drug delivery into the brain parenchyma.

Distribution in brain of liposomes after convection enhanced delivery; modulation by particle charge, particle diameter, and presence of steric coating.

We have investigated the role of diameter, charge, and steric shielding on the brain distribution of liposomes infused by convection enhanced delivery (CED) using both radiolabeled and fluorescent-labeled particles. Liposomes of 40 and 80-nm diameter traveled the same distance but penetrated significantly less than a 10-kDa dextran; whereas 200-nm-diameter liposomes penetrated less than 80 nm liposomes. A neutral liposome shielded by polyethylene glycol (PEG; 2 kDa; 10% by mole) penetrated significantly farther than an unshielded liposome.

HIV TAT Protein Transduction Domain Mediated Cell Binding and Intracellular Delivery of Nanoparticles.

Intracellular delivery of non-transported therapeutic agents has traditionally been thought possible only for low molecular weight (<500 DA) hydrophobic molecules. Higher molecular weight agents including oligonucleotides, proteins, DNA, liposomes, and nanoparticles do not readily enter the cytoplasm. However, the human immunodeficiency virus (HIV) trans-acting transcriptional activator (TAT) protein enters the cytosol by way of an 11 amino acid cationic peptide (TATp).